GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: PCPhack on September 14, 2018, 02:07:29 PM
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Here I will log additional modifications to my Bulldog to make it hunting ready.
Already performed in an earlier posted thread:
-TP opened and polished to .3 inches
-JSAR SS valve installed
-Initial tuning for 2 shots at 285 foot pounds with Nosler 145gr or NSA 142gr slugs
-Shot accuracy after the above modification s are here: https://www.gatewaytoairguns.org/GTA/index.php?topic=148197.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=148197.0)
To-Be performed in this thread:
-Increase porting to .328 Done
-Longer dogbone linkage on the bolt to seat slugs to edge of .328 porting Done
-Deepen scalloped out area of bolt to maximize port flow Done
-Switch to handmade steel cocking lever (Thanks Matthew). Done
-Polish and lube the hammer Done
-Polish trigger group Done
-Reduce trigger 2nd stage pull length Done
-Reduce trigger pull to ~1-2 pounds Done. 1lb, 4oz
-Clean and polish the barrel with polishing paste Done
-Fire lap barrel with Wheeler kit Done
-Inspect the barrel crown and rework/polish as needed Done polishing and looks clean under magnification
-Install 5 barrel supports Done
-Install Pitbull extended reservoir Done
-Install JSAR titantium extended reservoir for 4500psi Done
-Install Pitbull regulator with custom length ordered plenum spacer Cancelled
-Install Pitbull long moderator Done
-Retune Done
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Hammer complete, including a careful 90 degree polishing of the face edge where the sear catches the hammer.
Before and after pictures.
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Based on the efficiency of existing shots with the factory reservoir, I will have to increase efficiency and/or come down in power to 270 fpe or so, to get the 4 shots on regulation with a custom Pitbull plenum length (assuming 1cc per fpe expected especially due to the SS valve). I estimated the receiver volume, and volume lost to the regulator body itself though, so will try to get those calculated exactly. This is rough estimation so far, with 21 inch plenum tube (1 inch ID), leaving only 10 inches for reservoir plus regulator itself , with 3000psi setpoint. Yes, I am aware of the risks. Existing shots at 285 FPE are using about 250 psi per shot with the factory reservoir. I will be back with more exacting numbers and the plan. I will likely work on the TP sizing a bit more to eek out a little more efficiency.
Edit: Took porting to .328 for more headroom with the power and efficiency.
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4500PSI seems a little high for a Bulldog. Subscribed as I'm looking for improvements for my Bulldog.
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4500PSI seems a little high for a Bulldog. Subscribed as I'm looking for improvements for my Bulldog.
It is high. The valve body (and especially its threads) and receiver must withstand the full 4500psi. The valve is not held in with valve screws though, but rather captive in front of a smaller hole in the receiver. Of course, that is no guarantee that the receiver can handle it. At least anecdotally, other have had success without issue, but again that is NO replacement for proper pressure testing. I have understood the air tube has been tested to 10k psi, but not the entire assembly. It is important to understand that on this design, the valve thimble end threads (where the reservoir tube screws on) will always see the full 4500psi, while the receiver and rest of the valve body would see 4500psi in the event that the regulator failed (or in this case some psi between the 4500 and 3000 set point, since the plenum will be larger than the reservoir).
If anyone takes it upon themselves to exceet 3k psi, they do so at their own risk. The only claim for testing that I have seen in written format is that of the Pitbull reservoir up to 10k psi.
I am actually curious if JSAR has done testing to failure of their valve and its threads. If so, I am curious of the failure pressure.
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Trigger group set up outside the receiver, ready to start grinding, filing, and polishing.
A big thanks to Pitbull for their Youtube video. While it may seem obvious what to do, the video has good reminders about finer points like grinding and polishing in the right direction to preserve key angles on edges, and etc. There are a few ways to adjust trigger, so I suggest reviewing past work of others to decide what you want to do.
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4500PSI seems a little high for a Bulldog. Subscribed as I'm looking for improvements for my Bulldog.
It is high. The valve body (and especially its threads) and receiver must withstand the full 4500psi. The valve is not held in with valve screws though, but rather captive in front of a smaller hole in the receiver. Of course, that is no guarantee that the receiver can handle it. At least anecdotally, other have had success without issue, but again that is NO replacement for proper pressure testing. I have understood the air tube has been tested to 10k psi, but not the entire assembly. It is important to understand that on this design, the valve thimble end threads (where the reservoir tube screws on) will always see the full 4500psi, while the receiver and rest of the valve body would see 4500psi in the event that the regulator failed (or in this case some psi between the 4500 and 3000 set point, since the plenum will be larger than the reservoir).
If anyone takes it upon themselves to exceet 3k psi, they do so at their own risk. The only claim for testing that I have seen in written format is that of the Pitbull reservoir up to 10k psi.
I am actually curious if JSAR has done testing to failure of their valve and its threads. If so, I am curious of the failure pressure.
The valve and threads are not the weak point in the system they are more than capable of handling 4500psi its the air tube thats the weak point it is very thin where they threaded it and anything over 3200 psi is well below the 3 to 1 safety margin and unsafe.
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Thanks Travis.
They claim it was tested to 10K psi, so at 4500 psi, is only 2.22 times the working pressure. I am curious why they stopped at 10K psi, and what the actual failure point is or was (or did they actually go to failure).
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My power goals are in the opposite direction to yours. The Huma reg does not have much leeway with vent hole, so make sure you you have your plenum design final. That could be an expensive hole.
I would think that the BD hammer and spring are more than enough for a SS valve. A no pre-load and gapped spring might buy you some efficiency.
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Thanks Travis.
They claim it was tested to 10K psi, so at 4500 psi, is only 2.22 times the working pressure. I am curious why they stopped at 10K psi, and what the actual failure point is or was (or did they actually go to failure).
I would be curious if they had a failure at 10k my math says no but real world might be another story.
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I wish Pitbull published a test to failure video like JSAR did for the Marauder tubes. The material they used (2024 aluminum) and thickness would seem to indicate it is ok, but it needs more investigation!
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My power goals are in the opposite direction to yours. The Huma reg does not have much leeway with vent hole, so make sure you you have your plenum design final. That could be an expensive hole.
I would think that the BD hammer and spring are more than enough for a SS valve. A no pre-load and gapped spring might buy you some efficiency.
I am considering ordering the plenum tube a little long, and making the final tweaking cut after testing. The hole for the Huma is needed long term, but for a few shots at stable temperature, pressure, and altitude should be ok without it. I will definitely not drill the hole until I am certain where I want it.
The Bulldog hammer has plenty of mass for the JSAR valve, and the factory spring is too strong for the JSAR valve. I used up 10 dollars in slugs confirming it (should have started at the weakest end of the spring). Travis knows what he is doing, and the spring they ship with the Bulldog valve is perfect.
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I heard back from Pitbull. They tested only to 10k psi, because that is the highest their hydraulic pump could go, but it did not fail there.
I have asked them if they are willing to donate a tube to video being tested further if I can find a tester.
Edit: They are willing to donate only for a certified pressure tester who would also certify it. Anyone know of such a resource willing to play? I would guess that for a variety of reasons, a certification would not be free, even if the tester was willing to donate the time.
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Didn’t know Travis included a spring. You’re good then. Good luck with your quest.
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Thanks John.
I had a little shop time, so went out and did the trigger group tasks. Wow, in the picture with flash, you can still see it is not a mirror polish. To the naked eye it looks very smooth, and it feels very smooth. I lubed them and put the trigger group all back in with the pins. It is very smooth now, breaks on the second stage much sooner, and I did weaken the spring to ease the overall trigger force needed. ;D
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Extended reservoir preparation done. Here is how I opened the stock at the front. First, I put a few of the front screws into the two stock halves to hold it together. Then I used a large step bit, followed by 50 or so turns of 220 grit sandpaper taped to the oem reservoir. I have always liked how step bits make clean cuts in plastics, and is much faster than the dremel way.
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I used a bench grinder for the rough in, but alum tube and different grades of sandpaper to finish it off.
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=126825.0;attach=223341;image)
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That also looks very clean John! I have often used a bench grinder to shape plastic, but it's not my first choice for a circle. My largest step bit was almost perfect, but the hole needed to be just a tiny bit larger, thus the sandpaper.
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You’re really making me want a bulldog! Would really like to see some pics of the full gun as you go along for reference.
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It's still all apart right now, but will post some pictures of the whole gun once I start final assembling a bit more.
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I decided to take the porting to .328. This is as large as you can go without damaging the barrel retention grub screw hole threading in the top of the receiver. If one has a proper mill, they can get a few thousandths more.
Normally one would always fully spin up a press or mill before engaging the work, but even with perfect alignment via a pin down through the existing work, and also visual inspection, the runout and vibration on my press was tapping the grub hole threads. So in this case, I held the bit down into the hole fully, and spun up the press. This worked to keep the bit from cutting any of the threads. In the attached picture (not cleaned yet), you can see my test approach to the hole with the press fully spun up before the approach to the hole. Note the spot where the bit was trying to tap even when perfectly aligned (due to runout and vibration). Anyway, spinning up while already having the bit in the grub hole worked fine. I will try to do the barrel later today.
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I note that even with .3 porting, the bolt should really seat the slug a bit more, and especially now with .328. I have not seen another idea I have discussed before, which is to make a longer dogbone linkage for the bolt lever to bolt link. This will allow the bolt to seat the slug a bit more into the leade. Then, along with a slight relaxing of the actual bolt lever angle, will allow a slight more retraction of the bolt once the lever is locked down.
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Barrel ported to .328
Slight cupping from TP into barrel. Polished shiny.
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After dinner and a bit of family time, I will start assembly without the regulator for now. I want to run some strings on the chronograph without it, but with the larger reservoir. I am guessing some might be interested in non-regulated string results with the .328 porting and Bulldog reservoir, so I will post them here.
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Can't wait to hear what you get with the porting. This thread got me reading all about the bulldog (thanks PCPhack).
Watched a bunch of pitbulls videos and a couple THammers.
I really like when I saw the stock shroud removed/cut and just exposing the barrel. Looks perfect for a nice 1.25"/1.5" standard looking shroud with baffles.
Here's a guess of what I think your gonna get:
PSI FPE
2500 257
2600 267
2700 277
2800 288
2900 298
3000 308
I am seeing a good full mag with in 3% ES around 250fpe/275fpe.
Wish you luck and can't wait to see what you get.
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I received a drawing of the Bulldog valve end, and the threads where it goes into the tube are 1 3/16"-18, and the tube is 1 3/8" OD.... That means the wall thickness measured at the peak of the threads is only 0.094".... The O-ring that seals the valve to the tube is outboard of the threads, so the threaded area of the tube is pressurized.... I was told that the Bulldog tube is aluminum (grade unknown), but if we assure 2024-T3, which is the most common high-quality tubing available (and much stronger than 6061-T6), we can do the safety factor calculations....
At 3000 psi, using 1.375" OD x 0.094" wall, with 2024-T3 tubing, I get safety factors of 2.4:1 to Yield and 3.4:1 to Failure.... Based on the information given to me, I would not fill a Bulldog past the 3000 psi fill pressure recommended by Crosman…. If this information is correct, the tube should start to permanently stretch at the deepest cut of the threads at about 7,300 psi, and fail at 10,200 psi.... The problem with overfilling is that you are reducing the cycle life of the aluminum to the point where metal fatigue reduces the tensile strength of the aluminum to the point it fails.... As with any overfill situation, an accidental "oops" to 4500 psi,once, shouldn't be a problem.... Repeated use of that as a fill pressure, however, is very likely to eventually cause a catastrophic failure....
I am not an engineer, but I believe the above calculations to be accurate.... It is also consistent with the 3000 psi MSWP that Crosman state for the Bulldog.... Personally I would NOT overfill one....
Bob
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Thank you for running the numbers Bob. I can likely reach my goals without regulation of higher pressure than the 3k. The larger reservoir should give a smoother curve and lower ES than the stock one. Let's see.
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I was not given a drawing of the fill fitting at the front of the Bulldog reservoir.... but if it is the same threads and OD, in 2024-T3 aluminum, with the O-ring outboard of the threads.... then the same calculations apply at the front as at the back.... 3000 psi maximum fill pressure.... If the front is different, and someone wants to supply me with a dimensioned drawing, I can run the numbers for that as well....
I was told that the reservoir tube is a 1/8" wall (0.125"), and if that is the case, and IF the O-ring is INBOARD of the threads, so that they are NOT subjected to the fill pressure, then at 3800 psi (and once again assuming 2024-T3 aluminum) the safety margins are 2.6:1 for Yield and 3.6:1 for Burst.... Even with the O-ring inboard of the threads, I would personally never exceed that fill pressure forward of a regulator.... Note I am not recommending that procedure, Crosman's recommended 3000 psi fill pressure should still be used for safety.... Remember, we don't know what the tube is made of....
Bob
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Bob, the Pitbull extended reservoir has an airbow fill cap on the end. I took it out, and that end has an inboard oring. I have not taken the end off the factory tube to verify what it has.
That raises and interesting question. How does the math work out if there is, for example, 3800 psi at that end, but a regulator set to 3000 psi inside? Assuming the regulator is not in failure, the plenum side threads, with the outboard oring, see 3000 psi of air pressure, plus an additonal 800 psi of shear pressure from the reservoir side.
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I assume this is one of Matt’s (Lake Rat) longer tubes. It has BD threads on the valve side and airbow on the front, which are a different size. Not sure where the o-ring is on fill, airbow schematics are under downloads on crosman store.
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The reg pushes against a plenum tube which rests against the reducer fitting. So I think the BD thread side would be under plenum pressure.
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The reg pushes against a plenum tube which rests against the reducer fitting. So I think the BD thread side would be under plenum pressure.
Yes, this is known, but there are two kinds of pressure happening in this case, the pressure inside the plenum directly, and the shear pressure from the plenum spacer, which has the additional differential pressure (from the reservoir side) against it.
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This actually raises a second point...if orings that fit snug inside the reservoir are used at both ends of the plenum spacer, then the entire thread load at the valve side of the tube becomes shear. Of course, this is bad engineering since the orings are not properly seated in such a configuration, but it is fun to think about.
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My calculations on the shear strength of the tube threads indicate that is not an issue, the minimum safety factor is the hoop strength of the tube at the threads at 3000 psi.... The axial load on an ID of 1.125" at 3800 psi (eg. the end of the regulator) is 3777 lbf…. It depends on the exact thread engagement used, of course.... but the drawing I had for the Bulldog valve end showed an engagement of 0.45", and using that, and 2024-T3 for both tube and valve, the safety factor of the threads in shear at 3800 psi would be 6.7:1.... The axial loading on the tubing wall from the end force, however, is the weak part of the axial loading, at about 4.7:1 at 3800 psi....
I am not familiar with the "Airbow Fill Cap", so you are completely on your own regarding the safety of the Pitbull "extended reservoir".... Do you KNOW what the material is?.... Does it thread onto the Bulldog valve as per the original?....
The reg pushes against a plenum tube which rests against the reducer fitting.
NO idea what you mean by "reducer fitting".... If there is a joiner in the tube, all those calculations must be done too.... You are correct that providing the regulator is not bypassing, the Bulldog valve threads would be under plenum pressure (not to exceed 3000 psi)…. If the regulator fails, it would be nice to have the proper safety margin on the downstream side to stand the reservoir pressure.... but since this should be a rare / one time event, the normal safety margins should be adequate.... hopefully....
if orings that fit snug inside the reservoir are used at both ends of the plenum spacer, then the entire thread load at the valve side of the tube becomes shear.
Not so, because the pressure on all sides of the O-ring is equal, so they will not develop a seal.... IF you removed the outboard O-ring on the valve end, AND designed the plenum in such a way as to hold the O-ring in place against the front end of the valve, so that the seal was at the INBOARD end of the threads, you might be able to do what you suggest.... I see no reason to have an O-ring at the front end of the plenum, do you?....
Bob
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Bob, the Bulldog regulator is just a very short Huma regulator with its own 2 orings. The plenum size is then set via a section of tubing that glides smoothly inside the reservoir. This keeps the regulator from sliding all the way to the valve. He meant that this tube presses on the valve threading end, reduced area.
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Actually, one could remove the outboard oring with what I suggested! The orings at the ends of the plenum tube would be to keep all the air pressure inside of the plenum spacer tube.
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It is 3571-004 Reservior adapter, and goes from the larger tube OD to a smaller OD that threads into the receiver. The valve poppet spring rests against a shelf in the small OD end.
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Ahhhhh…. I guess that is the part I was sent the drawing of with the thread dimensions.... a Bulldog part, right?.... The 1-3/16"-18 threads I talked about that thread into the tube are on one end, and 15/16"-20 threads and 2 O-rings on the end the fits into the receiver....
Bob
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Ahhhhh…. I guess that is the part I was sent the drawing of with the thread dimensions.... a Bulldog part, right?....
Bob
Correct
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In this case though, I have an SS valve, so it is theirs rather.
The front end of my reservoir tube, indeed has different threads than a factory Bulldog tube as I understood it (for the airbow fill cap end), and an inboard oring.
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Actually, one could remove the outboard oring with what I suggested! The orings at the ends of the plenum tube would be to keep all the air pressure inside of the plenum spacer tube.
My plenum tube has a smaller OD then the ID of the res. I have o-rings around the OD of the plenum to keep it centered. I drilled holes in the side to make sure pressure was equalized, in case it pressure sealed on the front and back. It is just cheap hardware store aluminum tubing.
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Hold the phone, really? It is not the same high grade aluminum as the reservoir? Well forget all I wrote then...
My regulator hasn't come yet, but I wouldn't have believed the plenum tube is loose.
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Hold the phone, really? It is not the same high grade aluminum as the reservoir? Well forget all I wrote then...
My regulator hasn't come yet, but I wouldn't have believed the plenum tube is loose.
I purchased the reg from huma and made my own plenum or stand-off. I don’t know what Matt uses but didn’t think it was high strength tubing.
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Hold the phone, really? It is not the same high grade aluminum as the reservoir? Well forget all I wrote then...
My regulator hasn't come yet, but I wouldn't have believed the plenum tube is loose.
I purchased the reg from huma and made my own plenum or stand-off. I don’t know what Matt uses but didn’t think it was high strength tubing.
Ah, ok. I will ask.
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No need for high strength for a compressive load.
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I am curious though what material he is shipping for the spacer.
Well, I didn't end up doing any more work on the gun tonight, but the conversation was interesting.
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Can't wait to hear what you get with the porting. This thread got me reading all about the bulldog (thanks PCPhack).
Watched a bunch of pitbulls videos and a couple THammers.
I really like when I saw the stock shroud removed/cut and just exposing the barrel. Looks perfect for a nice 1.25"/1.5" standard looking shroud with baffles.
Here's a guess of what I think your gonna get:
PSI FPE
2500 257
2600 267
2700 277
2800 288
2900 298
3000 308
I am seeing a good full mag with in 3% ES around 250fpe/275fpe.
Wish you luck and can't wait to see what you get.
Thanks Tim. Hopefully I can come back tomorrow with some numbers. I have some 160gr slugs now to test, and with polishing, the ports are actually a bit over .328.
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Plenum spacers don't need to be super strong, but need to have enough wall thickness to withstand the compressive load.... and should be vented to prevent pressure buildup between them and the reservoir tube.... Imploded plenum spacer....
(http://i378.photobucket.com/albums/oo221/rsterne/Important/Tube3_zpsojmxqssy.jpg) (http://s378.photobucket.com/user/rsterne/media/Important/Tube3_zpsojmxqssy.jpg.html)
Motorhead has a photo of one that is compacted lengthwise into a VERY short, nearly solid cylinder.... :o
Bob
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Initial string with .328 porting
The power is about the same as before, but my earlier 2 shot string had an efficiency of .76. Now it is .99, although to be fair, that 2 shot string was at 285 FPE and using higher pressure.
I also needed a few turns more of the spring compared to before, even though I am using less pressure now. I suppose it is due to the larger porting.
Name: MP Bulldog JSAR Spring -2 turns from max. NSA 142gr slug
Notes: start , end 2688 psi
Shots: 5
Average: 923 FPS
SD: 3 FPS
Min: 920 FPS
Max: 927 FPS
Spread: 7 FPS
Power Factor Average: 131
Power Factor Low: 130
Power Factor High: 131
Barometric Pressure: 29 inHg
Temperature: 75° F
Weight: 142.0 grains
500cc reservoir
.99 avg FPE/cuin per shot
1 920 266.9
2 926 270.3
3 927 270.9
4 922 268
5 920 266.9
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The other test so far was one shot with the factory spring back in and turned all the way in minus 1 turn and . This made 330 FPE. Warning. Do not try this or your gun and you may explode. This was a 1 time test with me behind a blast shield.
I need time for more tests but the valve is acting different for sure with the larger ports. More spring from the above 5 shot string only makes a descending string as expected. I do believe this larger porting can reach a proper tune (2 or 3 shots at a plateau) at higher power with some valve adjustments, although I am tempted to just leave it right there.
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5 shots inside 8 fps! I wouldn't touch it.
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5 shots inside 8 fps! I wouldn't touch it.
Me either and you can still crank it up if wanted. NOW if I make a titanium tube and fill it to 4500 PSI that should yield nearly 400 FPE!!! Ill have to look over all the parts and see if the gun can handle that power level.
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Yes, I am a little surprised at that low ES, but I'll take it!
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5 shots inside 8 fps! I wouldn't touch it.
Me either and you can still crank it up if wanted. NOW if I make a titanium tube and fill it to 4500 PSI that should yield nearly 400 FPE!!! Ill have to look over all the parts and see if the gun can handle that power level.
Well get with it. You know I'd buy one. :D
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OK, at 4227psi, factory spring ran all the way in, JSAR valve (with jet as shipped), .328 porting,and a 145gr Nosler, it goes 1059fps for 361 FPE. ;D
Please be careful David I know its fun to stretch it out but that tube isnt rated for that pressure. Im looking for the Titanium tube now so dont kill yourself before I get it made LOL.
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That was definitely a one time deal. I hid behind a 1/4" metal shield. Lol
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That was definitely a one time deal. I hid behind a 1/4" metal shield. Lol
I bet it was loud as $%@#
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David,
Please be cautious with what your doing with well over the fill pressure and posting. There are a lot of knuckle heads out there and if they see that your running over 3000 psi they may think it's Ok.
Dude,
Please be careful. Seriously...... I am surprised a "safety" moderator hasn't stepped in yet with those fill pressure's. :(
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You are right. I will post a disclaimer on the earlier post as well. Moderators, if that is not enough, then please delete those posts.
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Well, I think i will tear it back down at least so far as to put the barrel supports in.
I still need to make the longer linkage piece for the bolt, but I may put it off. With the .328 port, the bolt should really seat the slug a bit deeper and retract a bit more. Both are doable with a linkage piece a few millimeters longer (I need to measure how much more exactly).
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Have Matt make a flow threw bolt that should pick up a few FPS for cheap
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OK, I confirmed a time to go shoot test strings tomorrow. I can't wait to see if all the work paid off a little, a lot, or heaven forbid worse in terms of accuracy. I will set the tune back to the great 5 shot one that I had. I will also come up with a slightly lower powered tune, time permitting. I need to wrap this up, as I am taking it hog hunting Friday or Saturday.
The regulator work and bolt linkage (or flow through bolt) upgrades are on hold. I may very well cancel the regulator with the great tune I got.
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Now delayed to go shoot strings as I had a leak. It developed after emptying the reservoir and then trying to refill, so I had to tear it down. There was a nick in an oring by the tube.
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Now it's ready.
I decided to just bunch up many of the barrel supports near the scope, one near the end, and another between those two points.
Picture of supports and then of fully assembled rifle.
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Better background
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Nice! Stuck with the 5 shot tune? Now we need an accuracy report.
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Well, I didn't get to shoot strings because I was well off the paper to the left. It was so far off at 20 yard that even running out my scope windage all the way, it was still several inches off. The only thing which could pull the barrel that far to the left is the Pitbull moderator. The scope is a known good one (and same as from my earlier accuracy test). Also, I did try reseating the scope and also further down the rail. Nothig helped. So my entire trip to shoot was a waste. I will take it and the barrel supports out, and retry on another day. :(
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Nice! Stuck with the 5 shot tune? Now we need an accuracy report.
Yes, the 5 shot sweet tune. See above though, something is wrong and it's shooting to the left.
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Well, I didn't get to shoot strings because I was well off the paper to the left. It was so far off at 20 yard that even running out my scope windage all the way, it was still several inches off. The only thing which could pull the barrel that far to the left is the Pitbull moderator. The scope is a known good one (and same as from my earlier accuracy test). Also, I did try reseating the scope and also further down the rail. Nothig helped. So my entire trip to shoot was a waste. I will take it and the barrel supports out, and retry on another day. :(
Bummer
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Well, now I confirmed it. I took off the Pitbull moderator, barrel supports, and extended reservoir (so that the DonnyFl moderator would fit again). Now it is back to centered with no problem to zero the scope. I kept the same 5 shot tune, except that now I only get 2 shots before the speed drops down. Good enough for hunting this weekend.
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Travis, how big is the hole in your flow-through Bulldog bolt?.... David is using porting that he says is the equivalent of 0.328".... That could easily be done by using a 9/64" bolt probe (I don't know what he is doing).... I ask because the wall thickness of a flow-through bolt for a .357 cal with a 0.328" hole would have to be less than 0.015"....
Bob
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Why wouldn't the slightly longer linkage for the cantilevered bolt be the easiest? It would then seat the slug deeper, and retract the bolt slightly more when the lever is all the way down, because the bolt plunges the deepest when the lever is around halfway, after which it starts to retract. The factory bolt has a nice scalloped out scoop in the end already to direct the air. It seems to me that it would make sense to use it as such and just modify the linkage piece to be longer. It's just a short dogbone shaped piece with a hole in each end.
To answer your question what I am doing now Bob, it is just the stock bolt with its scooped and to direct the air. If I was shooting pellets, the skirt would surely deform with the exposure of it in the TP. With the solid and boattailed slugs, it doesn't seem to hurt anything too much. I still want to work to set the bolt up to fully seat the slugs past the TP as it might still impact the shot more than I realize.
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Well, I just measured the groups I shot today. Mind you, I only had time to do a basic zeroing of the scope and then shot 3 groups. This is all I had time for.
I did try the 160gr Putbull HP slugs for a group. For me, they did not shoot well at 75 yards. 3 inch plus group. These are sized to .358, and they seat notably tighter, both by feel, and registered fps on the chronograph.
I then shot the 142gr NSA slugs and the 145gr Noslers. These both shot 2 inch groups at 75 yards. The NSA would have been a 1 inch group, if not for 1 flyer. In general, I see a half inch improvement over my earlier groups before the .328 porting, and more important to this topic, the trigger and extra polishing work.
I need to test and shoot more. I was very pressed for time today, and I am not 100% at all, having a nasty reaction to a wasp sting I got yesterday and the subsequent medication. Still, my groups improved, so I want to see how I do with more time and when I am at 100%. I will not do any more modifications until after the hunting trip Friday or Saturday.
In other news, I also ordered some 110gr and more 142gr NSA slugs. I got some in .356 and .357, so I can narrow down which is absolute best.
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Any luck on sourcing some Titanium tube Travis?
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Any luck on sourcing some Titanium tube Travis?
YEP!
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Hey, alright! I'll call you tomorrow. :D
Also would be cool to machine a block for the end to accept your double drop down, or in my case, stick one of my WAR bottle regulators in the end. Call it BottleDog :o
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Hey, alright! I'll call you tomorrow. :D
Im off tomorrow ;D going golfing with my buds.
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Ah, ok. Next week then.
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Pitbull has sent me a replacement moderator to try. Hopefully this one will work and allow my scope to zero. I will hold off on a titanium reservoir tube until I figure out if the Pitbull moderator is going to work for me, because if it will, then I will want the titanium reservoir tube to be as long as the end of the moderator. If not, then I will want it shorter so as to not extend beyond the barrel end.
Regarding ammo testing, I have ordered some .67 to .68 inch long NSA slugs to also try. These should come in heavier than the 142gr ones, while still fitting the magazine.
I will also retry the Pitbull 160gr slugs, except I will resize them to .357, as they come .358.
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If the Pitbull LDC doesn't work out, maybe give DonnyFL's LDC adapter for the Bulldog a try. This way, you can have a thread on/off LDC of any size made...
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If the Pitbull LDC doesn't work out, maybe give DonnyFL's LDC adapter for the Bulldog a try. This way, you can have a thread on/off LDC of any size made...
That is what I have been using prior to getting the Pitbull moderator.
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Ahhh... okay. I should have re-read the past posts! :-\
Travis: If you make those Titanium reservoirs available, will you be offering them in extended, factory, or custom length? Also, would they be using the airbow type filler or using the standard fill port? Would the end cap also be Titanium, or would we be re-using factory end caps? Not trying to hijack- I'm sure PCPhack would be interested in the info too!! ;D
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If the tube is larger, you can't use factory end caps....
Bob
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No no no. Same diameter tube, different length. Either end cap can be used (airbow or bulldog) except I have read they have different threading. I have both end caps, so could verify that. I would prefer the airbow because then I can still add a regulator (as then it needs to be filled from the end).
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Ahhh... okay. I should have re-read the past posts! :-\
Travis: If you make those Titanium reservoirs available, will you be offering them in extended, factory, or custom length? Also, would they be using the airbow type filler or using the standard fill port? Would the end cap also be Titanium, or would we be re-using factory end caps? Not trying to hijack- I'm sure PCPhack would be interested in the info too!! ;D
Complete custom set up no factory parts and rated at 4500 PSI more on it after I get material and some base testing done. Will have options on length and fill location.
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Ahhh... okay. I should have re-read the past posts! :-\
Travis: If you make those Titanium reservoirs available, will you be offering them in extended, factory, or custom length? Also, would they be using the airbow type filler or using the standard fill port? Would the end cap also be Titanium, or would we be re-using factory end caps? Not trying to hijack- I'm sure PCPhack would be interested in the info too!! ;D
Complete custom set up no factory parts and rated at 4500 PSI more on it after I get material and some base testing done.
Thanks Travis. I want to be first. :D Cash in hand.
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Ahhh... okay. I should have re-read the past posts! :-\
Travis: If you make those Titanium reservoirs available, will you be offering them in extended, factory, or custom length? Also, would they be using the airbow type filler or using the standard fill port? Would the end cap also be Titanium, or would we be re-using factory end caps? Not trying to hijack- I'm sure PCPhack would be interested in the info too!! ;D
Complete custom set up no factory parts and rated at 4500 PSI more on it after I get material and some base testing done.
Thanks Travis. I want to be first. :D Cash in hand.
I promise you will be David.
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Thanks Travis! Please see the thread in the JSAR subforum. I am getting stiction after it sits a while.
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David,
How did you fill the rifle from behind the blast shield?
Over filling is a fools errand, but going over that much I can't say how sad it makes me to read this in a public forum.
" oh oh I saw this one guy in this forum filling his ag to silly pressures and nothing happend..."
One bad section of tubing, too loose thread tolerance missed by the QC it takes only one mistake.
If it's not you, what about if the tube shoots through a door killing your kid or wife?
What more can I say.
Marko
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With a hose, how do you think? I do not test things in an unsafe way, or where any individuals would be at risk. If someone else is not following safe protocols, then it is their error. I have been working with compressed gas for over 20 years and am no idiot, thanks.
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Marko, I haven't been following this thread on a daily basis, but I must agree with you.... Regardless of the precautions David has taken, filling a tube designed for 3000 psi to 40% more than that is something that should not be posted on any public Forum.... JMHO....
Bob
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Yet it has sparked discussion, potentiated a titanium product option, and perhaps educated some. I would agree, the practice outside of confined tests is not be encouraged, obviously. However, I strongly disagree that information and education should be hidden or not discussed. There seems to be no issue to show a test video, for example, of testing something to failure, and yet then discussion of material limits should be discouraged?
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There is a HUGE difference between Hydrotesting an oil-filled tube to failure to know where that point is, or shear-testing valve screws using an hydraulic press.... and overfilling a reservoir with air, which when compressed stores such HUGE amounts of energy....
You say you have worked with compressed gasses for over 20 years?.... then you should know better.... ::)
Bob
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Bob was faster to type what I was about to...
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The smugness is palpable. It was just an example, and you well know that in industry all manner of tests are performed. This is entirely different from what day to day operation or usage ranges of a product will be. When I use my Bulldog that is for hunting, it sees no more than 3k psi. I have nothing more to say on this topic, and will remain an advocate for safe practices within accepted engineering safety parameters.
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My man just because you got away with it doesn't mean someone else can, this forum will not let any unsafe use of a airgun, this thread is locked until I get time to edit it. David
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I have now tuned the Bulldog for 2 shots at 250 FPE, and then slowly down from there. I have overcome most of the stiction by switching to a .015 jet on the JSAR valve, and using the factory hammer spring with a little over 2 loops cut off. This is with the factory air tube. The Pitbull air reservoir had a slightly non-squared end thay was blowing orings, so I took it off. The replacement arrived today, but it will have to go on next week, as we are hunting Friday night and Saturday morning.
The replacement Pitbull moderator solved my POI scope zeroing issue, and I even put the barrel supports back in.
I have also figured out that the rifle groups much better if I run 4 to 5 cleaning swabs through the barrel after approximately every 20 shots. It is now grouping around .75 inches at 75 yards somewhat consistently using custom NSA 130gr slugs (their 142 gr, only slightly lighter). Perhaps I will try to fire lap the barrel next.
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First hunt success (NSFW) can be found here:
https://www.gatewaytoairguns.org/GTA/index.php?topic=149485.msg1525504#msg1525504 (https://www.gatewaytoairguns.org/GTA/index.php?topic=149485.msg1525504#msg1525504)
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Though I am having excellent success with the NSA 130gr slugs, I have ordered some 165gr MrHollowpoint slugs, and will test them with the higher power tune (300+ FPE), along with 178gr NSA slugs (single loaded). I also have the replacement Pitbull air tube in hand, so will put that on while retuning. I can always come back to the existing tune, if accuracy is an issue. Stay tuned.
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I have a question for you david, my JSA bulldog vavle is not sealing after one shot, sounds like its burping or bouncing , I've talked to travis and he said to blow through the holes in the poppet stem to clear it , tried that didn't help, whats weird is it worked fine for about 50 shots while testing diff. Ammo, you stated yours was sticking earlier and you changed the jet in the valve, where did you find those jets , are they common carb jets?
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I have a question for you david, my JSA bulldog vavle is not sealing after one shot, sounds like its burping or bouncing , I've talked to travis and he said to blow through the holes in the poppet stem to clear it , tried that didn't help, whats weird is it worked fine for about 50 shots while testing diff. Ammo, you stated yours was sticking earlier and you changed the jet in the valve, where did you find those jets , are they common carb jets?
Were you using the stock spring?
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I have only seen or heard that with way too much hammer spring, or too low of a reservoir pressure for the current hammer spring setting. If you are using the factory spring instead of the one JSAR shipped with the valve, then you need to cut at least 2 loops off of the spring, because the factory spring is way too strong.
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Travis I'm using the spring that came with the valve, 2 turns in past flush with the back of the receiver, ported to .295 , I did notice a slight ni k in the rear oring on the poppet assy.barely feel it with a fingernail using a magnifying glass i can't see any damage but can feel it . Almost ready to put the stock valve back in but am afraid the poppet seal won't seal because of going past .277 on the porting
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I also polished the poppet stem with 1500 sand paper because it was binding when i first installed it. Wish the bulldog wasn't so difficult to take apart to work on ,hope the stock screws don't strip out from removing them so many times LOL
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The screws shouldn't strip. I have had mine apart probably 20 times. Also, the porting will not impact your ability the use the factory valve, unless you damaged the seat area somehow, in which case you would have a leak already.
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Travis I'm using the spring that came with the valve, 2 turns in past flush with the back of the receiver, ported to .295 , I did notice a slight ni k in the rear oring on the poppet assy.barely feel it with a fingernail using a magnifying glass i can't see any damage but can feel it . Almost ready to put the stock valve back in but am afraid the poppet seal won't seal because of going past .277 on the porting
Is the valve leaking when you cock the gun and air it up if so the valve will behave poorly and we need to fix the leak before any more usage.
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And if the screws strip or more likely the threaded insert will pull out, McMaster Carr sells a package of inserts.
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I also polished the poppet stem with 1500 sand paper because it was binding when i first installed it. Wish the bulldog wasn't so difficult to take apart to work on ,hope the stock screws don't strip out from removing them so many times LOL
The Bulldog is a joy to take apart, try a Hatsan Carnivore .3 or .357, then you will really appreciate the Bulldog. Regards, Tom
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Travis ,no the gun airs up fine. I only get one or two shots then it burps (the best i can describe the sound) and the vel drops off by 50 fps or so. Ive inspected all the parts can't see any foreign material or damage, guess I'll try the stock valve for deer season then return to the troubleshooting of the jsa valve,really liked the results I was getting before the problem
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Travis ,no the gun airs up fine. I only get one or two shots then it burps (the best i can describe the sound) and the vel drops off by 50 fps or so. Ive inspected all the parts can't see any foreign material or damage, guess I'll try the stock valve for deer season then return to the troubleshooting of the jsa valve,really liked the results I was getting before the problem
Before you waste a lot of time swaping valves i would call me at the shop its likely a simple problem we can address.
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Though I am having excellent success with the NSA 130gr slugs, I have ordered some 165gr MrHollowpoint slugs, and will test them with the higher power tune (300+ FPE), along with 178gr NSA slugs (single loaded). I also have the replacement Pitbull air tube in hand, so will put that on while retuning. I can always come back to the existing tune, if accuracy is an issue. Stay tuned.
I am back after another short break. I will pick up from here in the coming days to test these new slugs and I might move back to using the longer reservoir. Another hunt is coming up in a week and a half.
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First up on this round of work will be making a longer linkage piece for the lever mechanism so that the slugs will seat fully and the bolt fully retract from the .328 porting. I am not sure it will add much difference, but with .328 porting, those two conditions definitely exist.
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This one is .075" hole to hole longer than factory. It may be a few thousandths less as I did this prototype quickly. It probably should be a hair longer. You can see the test slug mostly seated, but still just peaking out from the TP hole. This is better than before though.
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David, I don't understand how a longer link can allow the bolt to retract further as well as load the bullet deeper.... Please explain....
Bob
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Bob, by itself it will not, but the plan is to adjust the angles on the lever as well (yeah I might foul it all up lol). The arm and pivot point at the end of that link needs to swing further past the centerline for more retraction. I will fiddle with it more tomorrow, as I had limited time tonight.
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Here is a not so good picture of the bolt, flipped over to show the scalloped area of the bolt, with the cocking lever seated. This hole is the same diameter as the transfer port below it. As the new linkage seats the slug deeper, I now plan to reshape and grind this scalloped area to allow better air flow, rather than change the lever mechanics to retract the bolt further.
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I probably have taken around 800 shots with this Bulldog, and this is a shot of the cocking arm pin hole. It is a bit concerning that it is already wallowed out of round. This part should be steel or otherwise reinforced, rather than plain aluminum.
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Much deeper scoop...
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Here is the new clearance view. I think that I will stop here for now with this linkage and bolt mod.
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Eh...good enough. This is slightly thinner metal than the factory link, so I will put a washer on either side. That will also keep it centered and from rubbing this paint off. ;D
If this works well enough, I may not even bother to have a proper stainless link made.
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Actually, the end of the dogbone link closest to the lever needs to be a little more narrow than I made it. I noted it now with the marking in the paint as seen here. It only keeps the bolt from retracting a tiny amount, but I will fix it.
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That cocking lever in Reply #116 appears to be on the verge of breaking, IMO.... Perhaps that has something to do with the testing you did at over 4000 psi, on a gun designed for 3000 ?!?!?....
This may very well be a perfect example of how important it is to address ALL safety aspects when considering increasing the operating pressure.... or caliber and hence operating force.... on any PCP....
Bob
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That cocking lever in Reply #116 appears to be on the verge of breaking, IMO.... Perhaps that has something to do with the testing you did at over 4000 psi, on a gun designed for 3000 ?!?!?....
This may very well be a perfect example of how important it is to address ALL safety aspects when considering increasing the operating pressure.... or caliber and hence operating force.... on any PCP....
Bob
Point taken, but I do not think this is the case. Two shots did not do that. It is worn down. If it had happened in two shots, I do not believe it would be so smooth. Anyway, a new one is easy enough to order. It may be that in general it will wear out with the modified setup that I have.
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I will concur that the warping of the pin hole has nothing to do with fill pressure. I don't overfill mine either yet it has also warped in the same manner. My guess is that when the spring tension is great enough, the thin aluminum cannot withstand the leverage and gives some. It wasn't an issue with mine until I started turning up the spring tension.
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Perhaps the wear is because it got bent from those two shots.... or perhaps not.... It certainly appears to be bent, it will be interesting to see how a new one compares when you replace it....
One of the problems with bolt lock-up mechanisms is not that they aren't strong enough to take the static (pulse) load on firing.... The problem is that if that mechanism fails, or it the gun is fired with the bolt not properly latched.... the bolt can accelerate backward at high "g" over the entire "sealed" distance (how far the bolt travels until the breech O-ring clears)…. and some distance after that, depending on how close the tolerances are.... This gives the (quite heavy) bolt a significant velocity and a very high momentum.... When it hits whatever is there to stop it, the instantaneous force it generates is much higher than the static force that launched it....
Think of a hammer, and the huge forces it generates when it comes to a halt against a nail.... There is no way you could push that nail into a board by hand.... and yet a relatively gentle swing of the hammer, generating momentum which comes to a sudden stop.... creates HUGE force....
It is easy to focus on one thing when looking at the safety of a PCP.... for example the tube strength, or the valve attachment screws.... while forgetting what other things we may be overstressing.... and the consequences that some other, unexpected failure could produce....
I'm as guilty as anyone, even though I try very hard to think of everything.... ::) …. I'll bet you have never fired your barrel through a Chrony, have you ?!?!?.... Setscrews that didn't bite properly into the very hard epoxy of a CF tube, a material that had a very low shear strength, were responsible for that.... and no, I didn't get a Chrony reading on it.... ;)
Bob
PS, is the spring tension from cocking not in the opposite direction on that lug/fork?.... I think that bend/wear is from bolt recoil....
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I believe the material is just too weak. By nature of the bolt dragging on the oring when it retracts, any play in the pin area there is opened up. Then upon firing, the bolt is slammed backwards, just as you explained Bob, and any small play is closed up. This back and forth wears the hole out over time, especially when it shoots slugs at around 50 percent over factory FPE. A small steel sleave or shoulder washer for this hole, epoxyed in place may be enough, but it is an awfully small area to modify like that. I would actually prefer an entirely stainless cocking lever.
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Is it possible to attach a ND magnet set under the lever? This may help/prevent it from opening when fired.
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I don't see how any magnet would help, as the lever doesn't come up any when firing. It can't actually due to the lock up of the bolt in a slightly retracted position when that pivot point crosses the center line of the bolt.
Looking at this closely, it may have some wear, but I think most of the oval shape is due to elongation of the hole, as in the aluminum has stretched here or bent as Bob put it. Hard to tell which. Maybe some of both.
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It very well could be both the force of cocking and the "blowback" of the bolt. Makes sense, seeing as how there really isn't a "locking" position, so to speak, of the bolt. Instead of locking into place, the arm simply returns back into a linear position behind the bolt when closed.There is plenty of room for failure to remain fully locked IMO.
I was thinking about getting with a CNC guy about making a new cocking lever and a retractable blot probe that would additionally lock into a milled slot on the receiver to further lock it down. I may have to do some drawing to figure it out but if it is feasible, heck, why not?!
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I will concur that the warping of the pin hole has nothing to do with fill pressure. I don't overfill mine either yet it has also warped in the same manner. My guess is that when the spring tension is great enough, the thin aluminum cannot withstand the leverage and gives some. It wasn't an issue with mine until I started turning up the spring tension.
You can see in this picture of mine, the handle hand area is also bent out a bit. This is from cocking it, so yes there is a lot of stress while cocking as well as during firing.
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It very well could be both the force of cocking and the "blowback" of the bolt. Makes sense, seeing as how there really isn't a "locking" position, so to speak, of the bolt. Instead of locking into place, the arm simply returns back into a linear position behind the bolt when closed.There is plenty of room for failure to remain fully locked IMO.
I was thinking about getting with a CNC guy about making a new cocking lever and a retractable blot probe that would additionally lock into a milled slot on the receiver to further lock it down. I may have to do some drawing to figure it out but if it is feasible, heck, why not?!
If several of us would want them, we could get a better deal than each getting a 1-off.
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I am game if anyone else would like to have one as well. I am working on a prototype for the bolt handle out of tooled steel that I started after my last post on the thread. I will start doing some drawing of a bolt with retractable probe as well and would be more than grateful for any other ideas or input. My thought is that the probe would extend past the concave of the bolt face about 1/4 inch that is easily retractable once cocked as well to ensure that the magazine can clear it. The part I have not figured out is the inlets necessary to lock it in without hampering loading a magazine or such but once the magazine is inserted, the probe would need to be fully extended to ensure it seats the round far enough and doesn't retract until I make it retract into the bolt after said round is chambered.
Any input would be appreciated. If it can achieve good enough numbers we may be on to something. The key is the retracting. I have experimented with several probed bolts already and so far only one design has had a significant increase of more than 40FPS. That being the 1/8 probe that is 1/8 at the rear and goes down in diameter to the tip. The issue is maintaining the concave on the bolt to help push the air in a forward direction instead of just straight up into the barrel.
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I will concur that the warping of the pin hole has nothing to do with fill pressure. I don't overfill mine either yet it has also warped in the same manner. My guess is that when the spring tension is great enough, the thin aluminum cannot withstand the leverage and gives some. It wasn't an issue with mine until I started turning up the spring tension.
You can see in this picture of mine, the handle hand area is also bent out a bit. This is from cocking it, so yes there is a lot of stress while cocking as well as during firing.
Oh yes, mine is quite similar! Mine even has a bit of a twist to it. Not great engineering on the cocking arm by any means.
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Mine is not hard to cock with the JSAR valve being balanced, but it is the very end of the cocking, getting the hammer to catch the sear, that I need to pull harder. Mine has always been like that even brand new out of the box. I might see about making it catch easier on the next disassembly.
By the way, the longer linkage piece actually exacerbates the above cocking, hammer, sear issue, so I will definitely need to address it. So everything is normal you know...touch 1 thing and need to adjust 3 others, lol. :D
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I agree. It isnt until its time for the sear to catch that it gets heavy. Perhaps a slightly heavier sear spring would help????
This is what I have so far from just brainstorming from the top see through view on a retractable probe.
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Following since I have a Pitbull and shoot lots so expect this wear eventually.
Add me as interested in a better made kit of bolt parts to retrofit.
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Sounds like the bend/wear may be increasing the effort right at the end of the travel because there isn't quite enough travel to get the sear to latch properly.... If this is not a problem on a stock Bulldog, possibly the hammer spring is too long / wire too big, and it's going coil bound.... I would think the longer link piece would indeed make the problem worse....
There is an old adage about modding PCPs.... Making a change often requires two more.... and each of those two more.... etc.etc…. Pretty soon you have created a monster....
Bob
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Very true Bob, a little takes more than we think sometimes. I was thinking the same that the spring could be binding but it's still the stock spring. Gonna have to look into that a bit more and figure out what to do about it. Perhaps the same weight spring with a coil or two less may solve it?
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I don't think it is due to the factory spring as mine has a few loops cut off. Before that, I was using the weaker JSAR supplied spring.
I think Bob was right here. The set point for the sear is at the end of the lever travel. When that hole starts to wear or stretch, the hammer is not quite pullled back enough to catch the sear. So you start having to exert more and more force to the lever that is already at the end of its travel, furthering the issue over time.
I am thinking to either build up the catch spot on the hammer so that the bolt catches it sooner, or to take a little off the hammer edge where the sear catches so that it catches sooner (while maintaining a perfect right angle as this is critical for sear function and safety).
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That may just do it. Just a minute of amount of clearance may solve the issue.
Here is what I have so far for the cocking lever. Mind you, it is still in the rough stage and since it was the first try at it, I bent it in the wrong spot. I may be able to heat it up and bend it where the yellow arrow points as it must be bent there to ensure that it locks when returned forward after cocking. If it won't bend where I want it to, I will have to start all over again. We shall see.
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Very cool! I am very interested.
I have started the retuning with the bolt that I ported the scoop open more. I also have the new Pitbull long reservoir back on it now (they had sent me a new one after my first was not square on the end). This looks like a healthy improvement already. Max power shot with 3000 psi, no more was exactly 300FPE! I tune mine for 2 equal hunting shots with a 3rd a bit less, so I can probably stay near this 300.
178gr NSA slug
871fps
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Good deal! I don't need more than two shot myself for hunting. Heck, be lucky to get off a second if needed.
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Just a thought. With that warping of the linkage pin hole, just as mine did, that may be why the sear is difficult to engage as it is keeping the bolt from coming back almost an 1/8th of an inch?..
The steel cocking lever should resolve that if that happens to be the case. I have enough steel to produce 10-15 of them. It is slow going as It's all done by hand with grinders, files, and a drill press but the first one should be finished up by noon. If it works properly on mine I will send you one to try out. After that, It will be an as needed thing that I will have to figure out a reasonable fee for with shipping.
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Mathew, that is correct, and what I was trying to describe. The stretched lever makes it worse, which then makes you have to pull back even harder to cock it, which then stretches it some more.
Looks good on the lever prototyping. Keep it up! I appreciate the manual work, but I also wonder what it would cost to model them and have some jetted/machined up with stainless. Perhaps JSAR would make one?
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
I've been following this thread with a lot of interest. I've been planning on modifying my Bulldog just like; well very similar to, what David is doing. However a couple things have been keeping me from getting started. The major issue is one that I have little control over. The other issue you guys have come up with an awesome solution! I'm on my third cocking handle. I've had the same problem with the linkage pinhole stretching out leading to the bending of the handle. While life is keeping me from working on my gun the stretching and bending of the handle is the only road block I'll be looking at when life allows me the time to do something for myself. I'm very interested in your improved steel replacement for the aluminum piece.
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Good job Mathew, and thank you. That's a kind offer. I could send you some slugs back. ;D
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
I've been following this thread with a lot of interest. I've been planning on modifying my Bulldog just like; well very similar to, what David is doing. However a couple things have been keeping me from getting started. The major issue is one that I have little control over. The other issue you guys have come up with an awesome solution! I'm on my third cocking handle. I've had the same problem with the linkage pinhole stretching out leading to the bending of the handle. While life is keeping me from working on my gun the stretching and bending of the handle is the only road block I'll be looking at when life allows me the time to do something for myself. I'm very interested in your improved steel replacement for the aluminum piece.
No worries David, I got you. I will produce them until I run out of steel. Probably 10-15 more. It does seem that the cocking handle is the biggest setback for anyone that is looking to soup up the platform. Shoot me a private message and we will discuss getting one out to you after the weekend.
PCPhack David, just finished up yours. Do the same with a private message and I will get it out to you after the weekend. Do you want me to leave it bare metal so that you can paint, polish, or blue it yourself? And hey, slugs work for me!!!
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PMed
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PM'd
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Got yours Carl. Coyote(David), I am not seeing yours.
Huh, who knew that we would figure out a solution and produce the new part right here in the thread?!!!! Good stuff!
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PCPhack(David), just finished up yours. It turned out nicer than mine honestly!!
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Hah. The later models have more practice and better quality. ;D :D Sweet.
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Got yours Carl. Coyote(David), I am not seeing yours.
Huh, who knew that we would figure out a solution and produce the new part right here in the thread?!!!! Good stuff!
I think I did something wrong with my first attempt to PM. Just sent another.
And Yes! Who Knew! You guys are great!
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Extractable probe doesn't look like it will work. Threading for bolt lug that makes hammer contact is in the way. But, we shall see. Back to the drawing board.
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You could make the mechanism retract more than the small amount it does by design by making one of those handles where the nub with the small hole that was wearing out is more of a short arm that extends out further. This will cause the bolt to retract further once the handle is closed. You would have to play with the angles and possibly linkage length a bit, and then machine a blunt end for the tip of the bolt, but it is totally doable.
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That makes sense.
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Headed out for a hunt tonight and in the morning with the 178 gr NSA slugs hitting at 270fpe. It was supoosed to be for 3 or 4 days, but had to shorten it.
If I have time, I will retest 142 gr NSA slugs with my current tune, as they are much flatter at 75 to 100 yards.
Edit: No luck, but someone else did with a hog. This was a very big 250 pound hog. I took the opportunity to see how the Bulldog did on the very thick shield area while we were cleaning it. The 178gr slug went right through, broke through a rib and into the vitals. Due to the particular way it was hanging, it wasn't possible to find an exit wound as it would have travelled into the far side shoulder or leg, and I am guessing it stopped in the middle somewhere.
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Talked with JSAR today and next up will be a custom length titanium reservoir for pressures up to 4500psi. 8)
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That begs the question.... will the factory cocking lever stand up to 4500 psi?.... If not, JSAR needs to make an upgrade one to go with the higher pressures, IMO....
Bob
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Talked with JSAR today and next up will be a custom length titanium reservoir for pressures up to 4500psi. 8)
Now that's something that I've been waiting for. Are you in line to get one?
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Thanks to ShakySarge, I have a steel one on the way (arrives today).
In general, it appears that the wear is from cocking, but the result is the same regardless; the worn levers are absolutely a probable failure mode.
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Talked with JSAR today and next up will be a custom length titanium reservoir for pressures up to 4500psi. 8)
Now that's something that I've been waiting for. Are you in line to get one?
Yes, just waiting on Jacob to post it.
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Thanks to ShakySarge, I have a steel one on the way (arrives today).
In general, it appears that the wear is from cocking, but the result is the same regardless; the worn levers are absolutely a probable failure mode.
Yes! So do I. And a big thank you to ShakySarge! I went through two levers while keeping my Bulldog in completely stock form and have never gone over a 3000psi fill. The first lever lasted only fifty shots. Truly looking forward to the new improved steel lever.
And looking forward to a new titanium reservoir, of course.
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
This is fantastic news! Very excited to hear more! Thank you for listening...
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
Good deal.
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ShakySarge lever vs. my old worn out one. Nice.
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ShakySarge lever vs. my old worn out one. Nice.
Good deal. Glad it got there. Let me know how it performs!
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
A little bird might have whispered something. Exciting times ahead guys.
In the meantime, I will focus on adding the titanium reservoir, and starting some experimentation around further accurizing the barrel. It shoots near to 1 MOA now, but I think it cam be further improved with a small tweak. I am having some ideas regarding drilling shroud bottom side holes and bedding the barrel in through them. As I already have barrel supports in place, they will be the framework. I have already modified the plastic breech shroud to be removable before the stock, so that I can then loosen the barrel screws, and slide the barrel and shroud out as one piece.
With regard to the above, I am researching different epoxies or other filler/adhesive and am open to suggestions.
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ShakySarge lever vs. my old worn out one. Nice.
Good deal. Glad it got there. Let me know how it performs!
It looks good, and I like that it is smaller around the back bolt, so that even with longer linkage, it should clear the plastic breech cover. However, it won't close. The nub for the pin should be centered so that the lever can be used in right or left hand configuration. Here in this picture, I tried to put it on for left hand, and the pin hits the breech opening. I will flip it over to right hand and try again.
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
A little bird might have whispered something. Exciting times ahead guys.
In the meantime, I will focus on adding the titanium reservoir, and starting some experimentation around further accurizing the barrel. It shoots near to 1 MOA now, but I think it cam be further improved with a small tweak. I am having some ideas regarding drilling shroud bottom side holes and bedding the barrel in through them. As I already have barrel supports in place, they will be the framework. I have already modified the plastic breech shroud to be removable before the stock, so that I can then loosen the barrel screws, and slide the barrel and shroud out as one piece.
With regard to the above, I am researching different epoxies or other filler/adhesive and am open to suggestions.
Don't waste your time what I have coming will fix all that need for bedding etc.
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It hits using it right handed also. I think I can put a thin washer underneath the rear bolt to shift it up just enough to clear, as there is just a bit of play.
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
A little bird might have whispered something. Exciting times ahead guys.
In the meantime, I will focus on adding the titanium reservoir, and starting some experimentation around further accurizing the barrel. It shoots near to 1 MOA now, but I think it cam be further improved with a small tweak. I am having some ideas regarding drilling shroud bottom side holes and bedding the barrel in through them. As I already have barrel supports in place, they will be the framework. I have already modified the plastic breech shroud to be removable before the stock, so that I can then loosen the barrel screws, and slide the barrel and shroud out as one piece.
With regard to the above, I am researching different epoxies or other filler/adhesive and am open to suggestions.
Don't waste your time what I have coming will fix all that need for bedding etc.
You always do that to me....lol. Thanks for warning me first this time though. I wasn't sure if the secret project was only the bottom half or also top/barrel half. Will all this retain the bullpup configuration? Ditching the shroud also? If so, custom cantilevered picatinny rail with tensioned barrel? ;)
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
A little bird might have whispered something. Exciting times ahead guys.
In the meantime, I will focus on adding the titanium reservoir, and starting some experimentation around further accurizing the barrel. It shoots near to 1 MOA now, but I think it cam be further improved with a small tweak. I am having some ideas regarding drilling shroud bottom side holes and bedding the barrel in through them. As I already have barrel supports in place, they will be the framework. I have already modified the plastic breech shroud to be removable before the stock, so that I can then loosen the barrel screws, and slide the barrel and shroud out as one piece.
With regard to the above, I am researching different epoxies or other filler/adhesive and am open to suggestions.
Don't waste your time what I have coming will fix all that need for bedding etc.
You always do that to me....lol. Thanks for warning me first this time though. I wasn't sure if the secret project was only the bottom half or also top/barrel half. Will all this retain the bullpup configuration? Ditching the shroud also? If so, custom cantilevered picatinny rail with tensioned barrel? ;)
It's just like Christmas! Oh my!
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Yes, Oldpro, please do keep us informed on these Bulldog mods.
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It hits using it right handed also. I think I can put a thin washer underneath the rear bolt to shift it up just enough to clear, as there is just a bit of play.
Now I am wondering if my breech is not gapped at the rear like it should be. Time to inspect my dog and see what the issue is. Can the side of the front holes be filed a bit to make it clear the pin?
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Eureka!!!! That was exactly the problem, the cheap aluminum lever! I have the first prototype completed and installed. Even with the hammer spring adjustment all the way in it cocks every time no problem. The issue was certainly that the aluminum had stretched just enough to prevent the sear from catching. I will make a couple more and you are certainly welcome to the next one no charge. Perhaps Travis will be interested in producing them in numbers. Either way, I will pump out some more for whoever else may want one in the mean time. Besides, it keeps me busy as I am fully retired and there isn't a lot to do in this town.
We are all over this! I think its very needed in high power applications. We don't have a bulldog in stock today but Tom Kerrigan is sending his in for this and a very secret project stay tuned.
Send it now, Travis? Regards, Tom
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It hits using it right handed also. I think I can put a thin washer underneath the rear bolt to shift it up just enough to clear, as there is just a bit of play.
Now I am wondering if my breech is not gapped at the rear like it should be. Time to inspect my dog and see what the issue is. Can the side of the front holes be filed a bit to make it clear the pin?
I solved it like this picture! One washer added.
All, this really is great. Before, I had to flex the aluminum handle back some to get the sear to lock up. Now it is just a smooth motion and it grabs the hammer really easy. Travis, I look forward to the machined solution you guys come up with, but in the meantime, thanks so much Matthew!
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Only this issue remains. It's a little too long and hits the breech plastic cover near the gauge. This only prevents a tiny bit of the bolt retraction, so might not matter. I will probably just grind it down a little to clear the bump.
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Only this issue remains. It's a little too long and hits the breech plastic cover near the gauge. This only prevents a tiny bit of the bolt retraction, so might not matter. I will probably just grind it down a little to clear the bump.
If you want, I can send you a new one. If you wish to just grind it a bit I am okay with that too. As I stated before, I would have never thought about the idea had it not been for your input! I agree that it makes the cocking sooooo much smoother and the lock up of the sear is crisp and easy compared to the bending piece of aluminum we were given from the factory!
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I'll just see if grinding it is enough Matthew. Thanks!
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Since the ideas are flying, how about a MDS hammer, with adjustable striker? As the factory striker goes down into a smaller circumference, recessed opening than the hammer itself down inside the breech, having an adjustable striker with a MDS hammer would give a buffer adjustment as well. I would buy one instantly Travis.
A bit off topic, but I am real close to ordering a Slayer 452, and if I get my hands on that will probably lose Bulldog interest. It could mean missed sales for JSAR if the parts come too slow. Hint, hint. ;D
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Since the ideas are flying, how about a MDS hammer, with adjustable striker? As the factory striker goes down into a smaller circumference, recessed opening than the hammer itself down inside the breech, having an adjustable striker with a MDS hammer would give a buffer adjustment as well. I would buy one instantly Travis.
I was thinking along the same lines. Possibly a Stopping Spring Guide is feasible?
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I have decided to have my custom length titanium reservoir not be any longer than where the actual barrel muzzle ends (actual barrel, not the shroud). There are a few reasons for this. The Pitbull reservoir is a bit longer, and mates up nicely to where their moderator ends. However, a longer reservoir means that only a very short moderator, like the Pitbull, will fit. I just noticed this morning that the 3d printed Pitbull moderator has chipped off. This one has maybe 100 slugs through it since I received it, and it itself was an exchange because the first one threw off my POI. I am sure they would exchange it again, but I will go back to my DonnyFL moderator. The DonnyFL one also screws off easier, if I want to shoot bolts. The second reason for a reservoir not to surpass the end of the barrel, is that I might some day switch the shroud out, and go with something else (come on JSAR). I don't want potential interference from the reservoir.
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Fascinating thread.
I ported mine to the original .277 that Tkerrigan had recommended, I have a new .30 bit, but when Tom K bored his out to .30 while testing some bullets for me, he only picked up less than 5 FPS.
I agonized also about that Tii tube length. I have two uppers, the original one is the .277 and has a short Pitbull on it. The second has the mega on it and both are glued on, a blow torch would be needed to remove them. I have broken a Pitbull once while removing it and I am hoping it will extend the life. Having said that, if the mega fails, I may just cut the barrel back to 22 inches so I can fling arrows with it.
Roachcreek
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I am thinking to go 24 inches on the titanium reservoir. That leaves about 1.75 inches of barrel beyond it (~1.5 with endcap), to accommodate a tensioning nut if I ever decide to do such a modification. It also leaves a bit of rail space on the factory shroud if I want to use it. Without any better input about future mods, that is the best compromise that I can think of. This will give around 385cc (389 with straight linear math of tube sizes scaled from factory claimed spec, but I believe it's closer to 385).
Other tube lengths for reference:
Factory: 20 31/32 inches (20.96875)
Pitbull: 30 7/32 inches (30.21875)
Note these are tube lengths, not including any end caps.
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Fascinating thread.
I ported mine to the original .277 that Tkerrigan had recommended, I have a new .30 bit, but when Tom K bored his out to .30 while testing some bullets for me, he only picked up less than 5 FPS.
I agonized also about that Tii tube length. I have two uppers, the original one is the .277 and has a short Pitbull on it. The second has the mega on it and both are glued on, a blow torch would be needed to remove them. I have broken a Pitbull once while removing it and I am hoping it will extend the life. Having said that, if the mega fails, I may just cut the barrel back to 22 inches so I can fling arrows with it.
Roachcreek
There are indeed diminishing returns on going larger with the port. The bolt begins to be in the way for increased flow, unless you also start modifying the bolt.
I should receive my titanium tube by Christmas.
I have some Air Venturi bolts, but have not tried them out yet. It is easy enough to pop off the moderator and front piece to test, but I just haven't gotten to it yet. I hope to try them this coming weekend.
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I think mine was 26.5" to keep it just short of the barrel, with the added airbow fill port and gauge.
If you are doing the airbow fill and gauge, the 2.5" for a short rail is probably not worth it. Anything there would block reading the gauge. A few more inches of airtube might better for you.
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=126825.0;attach=223342;image)
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I think mine was 26.5" to keep it just short of the barrel, with the added airbow fill port and gauge.
If you are doing the airbow fill and gauge, the 2.5" for a short rail is probably not worth it. Anything there would block reading the gauge. A few more inches of airtube might better for you.
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=126825.0;attach=223342;image)
I think that you didn't follow my logic. I chose 24 inches to make the reservoir end behind the actual barrel end, not the shroud end. I might be ditching the shroud all together in the future for a tensioned barrel and cantilevered rail. As such, I wanted to plan ahead now by not having a tube that is too long. In the meantime, with the factory shroud, it allows quite a bit of bottom rail still, if I want to use it. I am not planning to use the airbow fil port, although I do have one.
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Could your quest for a longer travel on your bolt be responsible for the Wear your seeing?
I played around with three different generations of Tagdaggers’arrow conversion on the AF Condor, it was hard to cock, really rough on arrows and so deadly accurate, it turned a pellet shooter into a weapon that could be used to humanely take any animal on the planet. The offshoot of Tagdaggers product was that you got to deal with Tagdagger, a finer gentleman than Dave is hard to find these days. However, the Bulldog/JSAR valve/Air venturing combo is far more user friendly than the Condor platform as you can use bullets or arrows interchangeably.
Roachcreek
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Lani, the bolt hole wear existed long before I started modifying the bolt travel. It is also a factor for non modified Bulldogs over time. You will even note that Pyramyd stocks them, but not all Bulldog parts. I am guessing it is because people are looking for them when their original starts wearing out.
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I missed barrel vs shroud. The airbow fill/gauge won't fit the standard BD tube threads, which I assume JSAR is providing. Is the plan to use a short piece of the shroud for scope mount or doing something more custom to mount to receiver?
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I missed barrel vs shroud. The airbow fill/gauge won't fit the standard BD tube threads, which I assume JSAR is providing. Is the plan to use a short piece of the shroud for scope mount or doing something more custom to mount to receiver?
I would guess no factory shroud at all, but a rail mounted back to the breech cantilever style, like a Slayer. Speaking of which, I may end up leaving the Bulldog as is shroud wise, calling it done after the titanium reservoir, and getting a Slayer .452. Then I would just use the Bulldog for when stalking around on the ground. I am waiting a bit to be honest to see what JSAR will release. I have a few projects ongoing, so will let someone else be the guinea pig on that one.
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A small bit of test feedback on my grinded out bolt, custom linkage, and metal cocking lever is that without the rear plastic on, the lever can drop a little more, which retracts the bolt maybe another half millimeter. The difference is 8 to 10 fps compared to the plastic on. So there is still some power to be had even after the grinding that I did!
Michael, want to try to make another lever, with the nub that the dogbone link attaches sticking out another 3/16" further compared to stock? That would give the little extra retraction and should not hit anything.
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Could your quest for a longer travel on your bolt be responsible for the Wear your seeing?
I played around with three different generations of Tagdaggers’arrow conversion on the AF Condor, it was hard to cock, really rough on arrows and so deadly accurate, it turned a pellet shooter into a weapon that could be used to humanely take any animal on the planet. The offshoot of Tagdaggers product was that you got to deal with Tagdagger, a finer gentleman than Dave is hard to find these days. However, the Bulldog/JSAR valve/Air venturing combo is far more user friendly than the Condor platform as you can use bullets or arrows interchangeably.
Roachcreek
I went through three without having modified a thing. I've noticed that quite a few people seem to believe that this problem is only caused by modifying the Bulldog. Well, that's all I have to say for now.
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Knowledge is power, thanks guys. I probably have not shot mine enough to show any wear.
Perhaps I will see if I can have a stock form of the bolt made of steel.
Roachcreek
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A small bit of test feedback on my grinded out bolt, custom linkage, and metal cocking lever is that without the rear plastic on, the lever can drop a little more, which retracts the bolt maybe another half millimeter. The difference is 8 to 10 fps compared to the plastic on. So there is still some power to be had even after the grinding that I did!
Michael, want to try to make another lever, with the nub that the dogbone link attaches sticking out another 3/16" further compared to stock? That would give the little extra retraction and should not hit anything.
Should be able to get it done and would only need to switch up the template used. Would you be saying 3/16” more towards the muzzle end or more towards the other side of the receiver?
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I suspect towards the muzzle at it would push the bolt just a little further in.
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Perhaps this image will help. Towards the thin line or the fat one?!
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Straight to the side or towards the thin line. We do need to make sure it doesn't retract too much, or the scalloped bolt tip will not seal past the barrel oring. I can make more precise measurements when it is back apart soon for the titanium reservoir. It is hands off time now, as I go hunting in a few days. ;D
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Travis, as I suspect you guys have a CNC professional lever coming, please consider to incorporate this idea of a longer nub to the side which will cause slugs to seat slightly deeper, and also will retract the bolt a little more. Everyone could gain a little power from it. Actually, with that nub change, one can keep the factory linkage piece while still achieving deeper seating as well as retraction.
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Travis, as I suspect you guys have a CNC professional lever coming, please consider to incorporate this idea of a longer nub to the side which will cause slugs to seat slightly deeper, and also will retract the bolt a little more. Everyone could gain a little power from it. Actually, with that nub change, one can keep the factory linkage piece while still achieving deeper seating as well as retraction.
+
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What ever it takes to make it work the best! I got your backs Guys Im listening.
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Travis, with the SS valve and .3 porting, what pressure gave the peak of the curve?
2600?
2700?
Something else?
(Hammer adj run in to 'no cock' then backed off 3/4 turn gives best for me with all bullet weights)
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Travis, as I suspect you guys have a CNC professional lever coming, please consider to incorporate this idea of a longer nub to the side which will cause slugs to seat slightly deeper, and also will retract the bolt a little more. Everyone could gain a little power from it. Actually, with that nub change, one can keep the factory linkage piece while still achieving deeper seating as well as retraction.
Been going over this in my head and while looking at the action of the bolt, linkage arm, and cocking lever. If the linkage pin hole was slightly more towards the muzzle it would both seat the bolt more forward and retract it a bit further. Extending it more towards the other side of the receiver would result in it not seating as far nor retracting more. If the factory ones that are bending are a sign, and I think they are, they show that the linkage pin hole tends to warp towards the butt of the receiver causing less forward seating and difficulty cocking. I really think that moving the steel lever's linkage pin hole forward towards the muzzle would get the desired result. Which, is why I think that the extended linkage arm you made was getting better results.
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If I have time between rebuilding and tuning a buddy's Mrod, I will experiment with both your theory and mine.
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Travis, as I suspect you guys have a CNC professional lever coming, please consider to incorporate this idea of a longer nub to the side which will cause slugs to seat slightly deeper, and also will retract the bolt a little more. Everyone could gain a little power from it. Actually, with that nub change, one can keep the factory linkage piece while still achieving deeper seating as well as retraction.
Been going over this in my head and while looking at the action of the bolt, linkage arm, and cocking lever. If the linkage pin hole was slightly more towards the muzzle it would both seat the bolt more forward and retract it a bit further. Extending it more towards the other side of the receiver would result in it not seating as far nor retracting more. If the factory ones that are bending are a sign, and I think they are, they show that the linkage pin hole tends to warp towards the butt of the receiver causing less forward seating and difficulty cocking. I really think that moving the steel lever's linkage pin hole forward towards the muzzle would get the desired result. Which, is why I think that the extended linkage arm you made was getting better results.
David "PCPHack" & Matthew & Travis,
If it helps; my experience (factory stock), the linkage pinhole stretched towards the butt. This lead to the bending of the aluminum factory lever due to trouble catching the "catch". This make sense? I hope this information helps in some way.
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What ever it takes to make it work the best! I got your backs Guys Im listening.
Thanks Travis!
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Someone with a damaged handle needs to send Travis one so he can troubleshoot it and redesign.
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Someone with a damaged handle needs to send Travis one so he can troubleshoot it and redesign.
I have a whole gun here now.
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Someone with a damaged handle needs to send Travis one so he can troubleshoot it and redesign.
I have a whole gun here now.
Good.
Then we can expect fixes and upgrades from the 'Skunk Works' development labs soon. 😊
I wonder if something like a different hammer with a PEEK striker and a SSG or TSS will be tested?
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Meat in the cooler.
NSFW
https://www.gatewaytoairguns.org/GTA/index.php?topic=152316.new#new (https://www.gatewaytoairguns.org/GTA/index.php?topic=152316.new#new)
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Coolers are packed!
NSFW
https://www.gatewaytoairguns.org/GTA/index.php?topic=152336.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=152336.0)
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And now I see the shipping notification from JSAR for my titanium tube. Awesome Christmas gift JSAR, thanks! ;D ;D ;D
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And now I see the shipping notification from JSAR for my titanium tube. Awesome Christmas gift JSAR, thanks! ;D ;D ;D
Your welcome and merry Christmas.
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The titanium tube should arrive tomorrow!
I am guessing that I settle on the 178 gr NSA slugs around 950 fps for 357 foot pounds. 357 from my 357. ;D That is, unless they can remain accurate at higher than 950 fps. The 130gr NSA (same design, just shorter) boattails started to lose accuracy for me when shot at 1000fps. It will be interesting to see how the 142gr and 178gr perform under high pressure.
I continue to find that my barrel gets 1 MOA of LESS accuracy after 2 or 3 dozen shots. If I clean the barrel, the groups tighten back up immediately.
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The titanium tube should arrive tomorrow!
I am guessing that I settle on the 178 gr NSA slugs around 950 fps for 357 foot pounds. 357 from my 357. ;D That is, unless they can remain accurate at higher than 950 fps. The 130gr NSA (same design, just shorter) boattails started to lose accuracy for me when shot at 1000fps. It will be interesting to see how the 142gr and 178gr perform under high pressure.
I continue to find that my barrel gets 1 MOA of LESS accuracy after 2 or 3 dozen shots. If I clean the barrel, the groups tighten back up immediately.
David, have you fire lapped your barrel? I had the same problem. I used the Wheeler kit with three different grits. Now it's not only more consistent but can shoot nearly three times as many times before cleaning is necessary.
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I have read about and plan to one day try the Wheeler kit, but haven't yet. I suppose I have put it off for concern over ruining the barrel.
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I have read about and plan to one day try the Wheeler kit, but haven't yet. I suppose I have put it off for concern over ruining the barrel.
I felt the same until I actually used it. It made me think I was about to take a grinder to it. But it takes so little metal off, think of it as a polish. Like taking felt and jewellers rouge to a soft gold ring to make it shiny again. I'm sure if a person went crazy with it you could do damage but unlikely. Just follow the instructions. Works great!
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Thanks for the reassurance. I ordered the Wheeler fire lap kit and added it to the list of modifications to perform in the first post. The kit should arrive by the weekend.
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Thanks for the reassurance. I ordered the Wheeler fire lap kit and added it to the list of modifications to perform in the first post. The kit should arrive by the weekend.
David, now I'm going to tell you what I should have in the first place. I did many hours of research over a period of a month. Too much research. I couldn't find any evidence of anyone destroying a barrel. I used 180 grain cast ammo. I prefer NSA swaged but the ammo I used had a lot of surface area to contact the barrel. I shot twenty rounds with each grit with a good cleaning in between each grit. I borrowed a bore scope and holly cow. It shined. The proof was that after shooting sixty rounds that accuracy hardly changed. I'm no professional but I hold my own. Hope this helps dispels any doubts.
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Thanks David! Feeling pretty confident now. Between the titanium reservoir and the lap job, my Bulldog will be ready for the next level. ;D
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Thanks David! Feeling pretty confident now. Between the titanium reservoir and the lap job, my Bulldog will be ready for the next level. ;D
I'm excited to hear how it turns out. I'm planning to do about the same...
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The next chapter is starting. ;D
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WARNING: THIS POST AND ALL FOLLOWING REFER TO MY CUSTOM BULLDOG UTILIZING A TITANIUM RESERVOIR. DO NOT FILL A STOCK TUBE FROM BENJAMIN TO MORE THAN 3000 PSI!
It is installed and pressurized to 4200 psi. I can tell right now that I probably won't use it over that or even 4000 due to practicalities of performing fills. Granted, the reservoir was empty, but my big tank was full at 4500, and could only get it to 4200. I won't want to have to run the compressor THAT often. Of course I will do a few shots at 4500 just to see what it can do.
We have guests coming over for the evening, so it will be late or tomorrow before I can post some numbers.
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Now this is getting interesting, and done properly with a safe custom airtube.
Pictures and shot strings please. ;)
Marko
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I am going to guess right now that it makes 375 FPE at 4500 psi. I know it will do a bit less with the tiny jet that I am using on the SS valve (to overcome first shot stiction with a smaller jet and more spring), and as it should do 400 with the regular or large jet. I can't wait to see what it really does.
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The force backwards on the bolt for a .357 cal at 4500 psi is 450 lbs. (50% more than stock).... a 3:1 safety margin means it should be able to stand 1350 lbs. of force.... Just thought I would mention that.... Stay safe....
Bob
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Bob, yes I believe that anyone trying this should consider beefing up the bolt system, lever, pins, and linkage. My linkage is steel, as is my lever, which is a good start. The pins are stock, and one ought to do the calculations for those shearing off, but we don't know the metal type. Anyway, yes I will be proceeding with caution.
In worst case, a pin could shear off and the linkage bust through the plastic housing where ones cheek is welded in firing position. For this, I am considering a metal plate over the area as an extra safety measure just in case that ever happened. Another idea is to drill horizontally across the breach behind the bolts seated position and then use a pin through it to limit the bolts backward movement ability, but that would be fiddly, and one might forget to set it. I need to study potential travel distances with the linkage all detached. Another outcome could be the bolt itself slamming further backward into the lever rear pin bolt area. At this point I am not sure it will be an issue though; the existing linkage pins may be strong enough.
Tests will come tomorrow. I won't go out and test while tired. The tube is pressurized, so I will see in the morning if everything has a good seal.
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The problem with a bolt/linkage failure is that the parts, once given momentum, become a hammer themselves, with all the consequences of that.... You can't push a nail into a board with your hand, but even a light hammer, swung gently, will generate enough impact force to drive the nail.... It all boils down to the conservation of momentum (the mass of the bolt being accelerated backwards by the air pressure) and how quickly it stops (the distance in which that momentum is lost to whatever it hits)…. Lloyd did an experiment a while back that showed an open bolt shearing through a 1/4" steel bolt, and bending a 5/16" one (if I remember correctly)…. It was crazy the impact energy the bolt had, and what it took to stop it....
Bob
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Physics 101: Equal and opposite reactions!
I'm eagerly following this to see what you guys come up with to determine the limits of the strength of the stock action and what can be done to beef it up, if anything.
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Initial tests with me taking cover for safety. Some may be disappointed here, but note the small jet I use to combat stiction, which cuts down on the FPE.
In earlier tuning, I had cut 2 loops off of my factory spring. With the smaller than as shipped jet that I am using on the SS valve and this cutdown spring, the peak of the curve is 4200 psi. As such, I can't perform a maximim test right now. However, this yields a nice 2 shot tune which is what I use for hunting anyway. This is with the cut down spring turned all the way in. Both shots were exactly 1004fps, so one shot on each side of the curve. This is 318 fpe and more than enough (and would be around 328 if shot at the peak at 4200 psi). Note that in earlier testing I always saw over 50 FPE less with the tiny jet that I am using now, but the upside is that I have no stiction issues after the gun sits a while, which is critical for hunting. I would have to order a new uncut spring and open the jet back up to do a max test.
Travis, if you guys have factory springs, or just stronger ones, then I probably will get them for further testing.
In other thoughts, I may even back the tune down some as I have ran the compressor twice today topping off the tank. Lol.
Name: Ti Test 142gr
Notes: 4400 end 3834
Shots: 2
Average: 1004 ft/s
SD: 0 ft/s
Min: 1004 ft/s
Max: 1004 ft/s
Spread: 0 ft/s
Power Factor Average: 142
Power Factor Low: 142
Power Factor High: 142
Barometric Pressure: 29 Hg
Temperature: 59F
Weight: 142.0 gr.
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After the string. You can see the speed and psi at the end. I have ordered some Realtree Xtra vinyl wrap to cover the few inches of air tube that extends from my stock.
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A bit of feedback for anyone considering the titanium reservoir; it adds a very noticeable weight increase. Consider very strongly to just take the factory length and not longer like mine is (3 extra inches) if this may be an issue for you. I can really tell the difference while free holding the rifle. Granted, with the bullpup design it's not really a big deal, but some may not like the slight weight increase.
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Another observation is that I get about 10 less FPE with with 178gr NSA of the same design as the NSA 142gr slugs. I believe it is due to barrel friction, as the slug is much longer. I will retest that after fire lapping the barrel (kit should come tomorrow). I may need to get a 356.5 die, as these are 357, but with 356 I lost accuracy. Benjamin Noslers at 145gr shot within a few FPE of the 142gr NSA slugs.
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The force backwards on the bolt for a .357 cal at 4500 psi is 450 lbs. (50% more than stock).... a 3:1 safety margin means it should be able to stand 1350 lbs. of force.... Just thought I would mention that.... Stay safe....
Bob
Thanks Bob. Very good to know. I too am planning to upgrade to the titanium air tube.
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The force backwards on the bolt for a .357 cal at 4500 psi is 450 lbs. (50% more than stock).... a 3:1 safety margin means it should be able to stand 1350 lbs. of force.... Just thought I would mention that.... Stay safe....
Bob
Thanks Bob. Very good to know. I too am planning to upgrade to the titanium air tube.
I think for myself, I will settle on something less than 4500. More like 4000. This is still 34 percent over factory. Filling to 4500 is just too impractical when 4500 is my tank pressure.
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The force backwards on the bolt for a .357 cal at 4500 psi is 450 lbs. (50% more than stock).... a 3:1 safety margin means it should be able to stand 1350 lbs. of force.... Just thought I would mention that.... Stay safe....
Bob
Thanks Bob. Very good to know. I too am planning to upgrade to the titanium air tube.
I think for myself, I will settle on something less than 4500. More like 4000. This is still 34 percent over factory. Filling to 4500 is just too impractical when 4500 is my tank pressure.
I was thinking the same thing. My compressor and SCBA tank both max out at 4500 and having to constantly top off would be a pain.
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I think that is why most PCPs running more than 3000 psi use a 250 bar (3600 psi) fill.... sometimes 3800....
Bob
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Anyone got an Finite Element Analysis program that could build a model and run the loads and stresses?
Solidworks would do it great but I don't have access any more. Or maybe Autodesk
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Deleted. Info was wrong. See next post.
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I noticed some strange fluctuation in numbers after lunch, so decided it was time for a first inspection. Low and behold the linkage bent. Here is the custom linkage piece that I had made from steel. Note it is a bit thinner than the factory one. I suggest a higher strength steel one that is full thickness to go along with a custom steel lever. Are you listening Travis? I don't think the factory one will hold up. The picture is only after about 20 shots at this new higher power level.
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I noticed some strange fluctuation in numbers after lunch, so decided it was time for a first inspection. Low and behold the linkage bent. Here is the custom linkage piece that I had made from steel. Note it is a bit thinner than the factory one. I suggest a higher strength steel one that is full thickness to go along with a custom steel lever. Are you listening Travis? I don't think the factory one will hold up. The picture is only after about 20 shots at this new higher power level.
I was wondering if it would hold up at those pressures. One step at a time though, I am sure JSAR could pump out some high strength ones. However, it also makes me wonder how much pressure the aluminum receiver can take. Kind of like working on an old car in a manner of speaking. Solve one problem, and suddenly another one takes it's place. Perhaps some A7 steel hardened once is in order???
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Welcome to modding PCPs.... each mod means two more, those two a couple more each.... and pretty soon the original idea is buried under a "to do " list.... ::)
Bob
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Yep. I've seen it several times already in my short few years of PCP rifles. I sort of expected it and was going to just be surprised if it actually held up. Nope. :D
I have to tear it down tomorrow anyway to put the camo wrap on the exposed tube. I will probably put the factory link back on to see how it hold up. I may or may not pull the jet also to see some max figures. Michael, your tool steel lever is fine. ;D
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I noticed some strange fluctuation in numbers after lunch, so decided it was time for a first inspection. Low and behold the linkage bent. Here is the custom linkage piece that I had made from steel. Note it is a bit thinner than the factory one. I suggest a higher strength steel one that is full thickness to go along with a custom steel lever. Are you listening Travis? I don't think the factory one will hold up. The picture is only after about 20 shots at this new higher power level.
Im working on it now.
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I noticed some strange fluctuation in numbers after lunch, so decided it was time for a first inspection. Low and behold the linkage bent. Here is the custom linkage piece that I had made from steel. Note it is a bit thinner than the factory one. I suggest a higher strength steel one that is full thickness to go along with a custom steel lever. Are you listening Travis? I don't think the factory one will hold up. The picture is only after about 20 shots at this new higher power level.
Im working on it now.
My man! ;D ;D ;D
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Welcome to modding PCPs.... each mod means two more, those two a couple more each.... and pretty soon the original idea is buried under a "to do " list.... ::)
Bob
Isnt that a fact Bob its never ending it seems.
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Welcome to modding PCPs.... each mod means two more, those two a couple more each.... and pretty soon the original idea is buried under a "to do " list.... ::)
Bob
Isnt that a fact Bob its never ending it seems.
Job security for some. Activity to keep others out of trouble (with wives and girlfriends)?
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Oh my, that link is doomed from the start, its sheetmetal. Needs to be something way more beefier than that.
Marko
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Yes, a typical "column buckling" type of failure.... It needs to be made a lot wider (in the middle in particular) to survive the end load.... What will be next once that is fixed, the pins shearing off?....
Bob
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Don't be all doom and gloom guys. ;D That's the reason for this thread, to beef it up. I plan to settle on a fill likely around 3800, but would like a safety factor of 3 at 4500, for the safety and reliabity.
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My fire lap kit is arriving today, as well as camo wrap for the titanium reservoir. In the meantime, I also need to drill new mounting holes for my compressor motor. I have ordered a new belt, as well as a US sourced slightly longer belt, and so need to be able to tighten out the slack. The several fills of my tank in the last few days to test the titanium Bulldog reservoir has my old belt slipping and it is already tightened all the way. Lol. There is always something to work on with this PCP gun hobby. :D
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Not all doom and gloom, just trying to keep you, and anyone reading this thread, as safe as possible.... What is the diameter of the smallest pin which is in shear?.... I assume it is steel?.... It it appears to be steel or stainless steel, and is non (or weakly) magnetic that can give us some clue as to the grade of stainless.... If it's highly magnetic, then we can only assume steel.... If you run a file across the end or the head, you may be able to tell if it is hardened or not....
Bob
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Don't be all doom and gloom guys. ;D That's the reason for this thread, to beef it up. I plan to settle on a fill likely around 3800, but would like a safety factor of 3 at 4500, for the safety and reliabity.
Well then you need to dig out your calculator and start doing some math on cutting loads for the pins and remember that its not static load case you need to calculate but dynamic.
Or use some 3D-CAE software to do the structural analysis for you. But you need to model your parts for it.
Marko
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Don't be all doom and gloom guys. ;D That's the reason for this thread, to beef it up. I plan to settle on a fill likely around 3800, but would like a safety factor of 3 at 4500, for the safety and reliabity.
Well then you need to dig out your calculator and start doing some math on cutting loads for the pins and remember that its not static load case you need to calculate but dynamic.
Or use some 3D-CAE software to do the structural analysis for you. But you need to model your parts for it.
Marko
Exactly...
See post #240
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Here we go again. ::) Do we need to go the route of locking the thread again since so many like to assume that others don't know what they are doing or calculate these things? I don't need to dig out anything. I posted the failing link specifically to warn those that may try things they should not. It was a piece made in half an hour to test slug seating, not for dangerous field shooting with it.
There is far more going on than what I post here about, and I really don't care for the attitude. If you have time and desire to recreate the calculations already done and then make the posts, then go for it. That would be far more benefitial to those needing or wanting to see the work than trolling.
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Oh my, that link is doomed from the start, its sheetmetal. Needs to be something way more beefier than that.
Marko
Wrong. As well, it was made to test slug seating and actual output changes in an agile way (quickly) in a safe environment. Factory pressures and linkage only have been used for field use at this point only. There is no sense to have machined a fine part for such a test. It was made for 3000 psi and had no bending at all even for test purposes at that pressure. It served its purpose and I used it in my preliminary higher pressure tests. Of course it bent. Water is also wet.
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This has been a really great thread. Let's try to finish up the year on a positive note. ;) ;) ;)
pv
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I have the factory length tube ordered from JSAR so I hope this thread stays open.
This thread will let me decide if I need to regulate.
I keep my Bulldog hammer down on a empty chamber with the magazine loaded with four 178’s or 120’s that I cast. If I can get 4 regulated shots I will be satisfied. I called JSAR yesterday about a regulator and was told that a regulator kit is in the works, so at this point for me the two more mystery mods you guys write about will be a beefed up lever, my bolt linkage seems to be as tight as it was when I got it new, and a regulator set at around 3500 Psi and use a 4200 psi fill, but those pressures and expectations may come down some as this thread hopefully continues. I did order a replacement lever from PA Just in case.
I have not shot mine at these uber pressures, however I seem to use around 200 psi each shot with .270 porting and the JSAR valve and spring used as received.
Roachcreek
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I have the factory length tube ordered from JSAR so I hope this thread stays open.
This thread will let me decide if I need to regulate.
Matt at Pitbull has done some high pressure reg testing. You can probably interpolate from some of his data. He had some videos out there.
Just for an awareness perspective, a reg will need a front fill. You would need to machine the aluminum end cap for a foster fill, or have the tube made threaded for the airbow fill assy/gauge. Both might be awkward on a standard length tube. ie more cutting around the plastic shell for fill access. Adding a few inches so it at least extends past that point, maybe worth it. A reg with plenum, even at those pressures, is going to eat 5-6" of airtube. Just something to consider.
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JSAR told me they are working on a regulator “kit”, hopefully the final product will be designed for their tube.
I doubt that I will take it past 3500 psi until we learn more Or that regulator kit is available.
I had some sleepless nights regarding that JSAR tubes length.
Matt is a great guy and has great products.
Roachcreek
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I have the factory length tube ordered from JSAR so I hope this thread stays open.
This thread will let me decide if I need to regulate.
I keep my Bulldog hammer down on a empty chamber with the magazine loaded with four 178’s or 120’s that I cast. If I can get 4 regulated shots I will be satisfied. I called JSAR yesterday about a regulator and was told that a regulator kit is in the works, so at this point for me the two more mystery mods you guys write about will be a beefed up lever, my bolt linkage seems to be as tight as it was when I got it new, and a regulator set at around 3500 Psi and use a 4200 psi fill, but those pressures and expectations may come down some as this thread hopefully continues. I did order a replacement lever from PA Just in case.
I have not shot mine at these uber pressures, however I seem to use around 200 psi each shot with .270 porting and the JSAR valve and spring used as received.
Roachcreek
You might get by with regulation with those 120s. I don't believe there will be enough reservoir air to regulate with the 178s and also keeping a desirable fps with them. I decided to skip the regulator due to a few reasons. Mainly I hunt with mine, so only 1 or 2 shots really need to be exact. This is easy to do without regulation and I practice shoot tethered. Second, I can compensate any first shot stiction while unregulated with the tune and set pressure. This is more difficult to manage with a constant pressure (one less variable to use leaving only hammer strength and jet size). You will certainly need a large plenum, which will increase tube sizes and weight even more.
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No doubt. Just can't make tubes longer afterwards. ;) It was just something to consider.
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Yes they are hard to stretch, I doubt anyone here has the Acme Ti tube stretcher. :D
They are machining the tube next week, gives me a few days to think about it, however it looks like a regulator and the factory length tube is not an efficient option.
Thanks for the info, lot cheaper to learn now than later.
Roachcreek
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It might be worth it for shooting a few magazines of lighter pellets.
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This has been a really great thread. Let's try to finish up the year on a positive note. ;) ;) ;)
pv
:D YES, I'm with you. My own project is highly dependent on this thread.
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Thanks all. I like to think that the posts are harmless, but they certainly come across as condescending at times. The forum certainly has a certain clique like atmosphere at times and I have seen more than one forum ruined by that. It's a topic for another thread, but yes I would like to continue. I already diverted my sponsorship and giving for this year elsewhere due to the last time around.
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Just a small update between some family time. Here is a shot of an updated gauge for the higher pressures. Your favorite vendors can probably supply these. I do wish a digital one in NPT threading was available though for my Brod builds (other topic), but not really needed for my few shot hunting Bulldog. In fact, the SS valve has such a nice plateau that I can set the pressure within few hundred psi range, and the shot power is with a few fps every time.
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Dude, you got me all wrong there. It was not my point to mean any disrespect, just if wanting to do it the right way on engineering point of view you need to calculate all the loads in the system.
And that linkage made of sheet metal, well if it is ment for testing something else then why shoot with it?
Marko
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Thanks Marko. Perhaps I just read it wrong. You and guys like at JSAR do excellent machining, and have access to great equipment to do that. I applaud the skills needed to then make the most of those tools. My point is that just because some like myself has modest tooling and machining skill, doesn't mean that I don't take safety precautions and also do the math. I let JSAR or similar shops make the pretty and final parts I want after hacking around to learn what all I want.
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No criticism was intended from my comments. I just do not know what you have calculated or not.
I tend to push the edges in my projects but have an education from the "School of Hard Knocks" [Percussion U, haha], which biasses me toward real engineering and not seat of pants experiments which have bit me in the rear a few times (I'm not a hard learner but it's those '1st time and no experience' things where I don't know what I don't know that I was thinking about.)
I am REALLY respectful of the potential energy contained in HPA, having worked in industry using 5000 PSI hydraulic and pneumatic systems. {And even experience with high pressure steam}
I respect your being an explorer and you sharing your development benefits the airgun community, so thanks!
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Thanks Carl. The truth is that even if I post the estimated pin and rear lever bolt shear strength it is just that, a guess. There is no way to definitely know unless one does some serious analysis of sample pins and bolts from Benjamin. This is because nobody is going to divulge the information, for liability reasons, and also why I won't post it on this thread. This means the only way to be sure on the safety is to replace said components ALL with known ones of a size calculated safe for the higher pressure and sourced from a trusted source. This is why I mentioned a protective metal plate as secondary protection, not as a primary "save my butt because it was half engineered measure," but because even NASA can make an engineering mistake and with safety, secondary sageguards as a safety net are a good idea. I have witnessed at least one HPA explosion of a high pressure hose right next to a guys ear once and it was scary as *(&^. I can't imagine a piece actually letting loose and shooting shrapnel or a bolt like a super heavy projectile. :o
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Thanks Carl. The truth is that even if I post the estimated pin and rear lever bolt shear strength it is just that, a guess. There is no way to definitely know unless one does some serious analysis of sample pins and bolts from Benjamin. This is because nobody is going to divulge the information, for liability reasons, and also why I won't post it on this thread. This means the only way to be sure on the safety is to replace said components ALL with known ones of a size calculated safe for the higher pressure and sourced from a trusted source. This is why I mentioned a protective metal plate as secondary protection, not as a primary save my butt because it was half engineered, but because even NASA can make an engineering mistake and with safety, secondary sageguards as a safety net are a good idea. I have witnessed at least one HPA explosion of a high pressure hose right next to a guys ear once and it was scary as *(&^. I can't imagine a piece actually letting loose and shooting shrapnel or a bolt like a super heavy projectile. :o
It's like the old saying "Think smarter, not harder".
Keep up the good work!
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You can easily change the hinge pins to something with known material. Dovel pins, or something similar.
Marko
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Yep, and they are readily available. Double v in English. I am closer to you Marko than you know. I wonder how many native English speakers actually never realized that W is actually double V to some other than just the looks of it :D
Various dowel pins can be had even right off Amazon, although I trust an industrial supplier much more when it comes to claimed metal type.
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For those that are interested, here is data for the rear linkage pin which attaches the lever to the dogbone shaped link. I won't make any strength claims due to liabilities as earlier stated.
The pins are ferrous upon a magnet test. They slightly file away as per the attached photo, a bit more than known hardened steel, but way less than a generic steel piece. A single rake of the flat file around the edge was performed and three times where you see a bit filed down. Sizing is 1/8 inch diameter on the pin body. I still prefer known sourced new pieces but did my testing with these factory pins. Take it as you will at your own risk. A known dowel pin machined at the ends to take retaining clips would be easy enough.
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David, thanks for taking the time to supply the information on the pin.... You say you did the math, and I'll take you at your word.... This post is not to lecture you, but for the enlightenment of others I will go through the process.... Note, I am NOT an engineer, but these are the steps you would normally go through to ascertain the suitability of a component.... NOTE: David caught an error I made in the tensile strength of 1144, the strikeouts and corrections are made below.... :-[
Using a medium tensile steel (1018 alloy) which is 64 Ksi tensile strength, the shear strength is calculated as 60% of that, or 38,400 psi.... the cross sectional area of a 1/8" pin is 0.0123 sq.in.... so the load to failure calculates to (38,400 x 0.0123) = 471 lbs.... Using a 3:1 safety margin, that means an allowable load of (471/3) = 157 lbs.... If the pin is 1144 Stressproof (about as good as steel gets without heat treating) then the tensile is 144Ksi 115Ksi, the shear strength is 86.4 Ksi 69Ksi, and the load to failure increases to 1063 lbs 849 lbs., and with a 3:1 safety margin the safe load is 354 273 lbs....
The area of the .357 cal bore (and so, presumably the front of the bolt) is 0.100 sq.in. so at 3000 psi (factory recommended) that is 300 lbs. of force backwards on the bolt upon firing, and at 4500 psi it is 450 lb. of load.... Assuming a very good quality pin, Benjamin likely did their homework and the pin should therefore be safe at 3000 psi (if it's not, blame Crosman).... However, even using 1144 Stressproof (and we have no idea if that is the quality), and a 3:1 safety margin, that would limit the MSWP to about 3500 psi 2700 psi.... If you use a hardened dowel pin you could easily get to 3000 psi MSWP....
What I am saying is that I would not exceed 3000 psi unless I know that the pin in question is up to the job.... and we can't know that because we don't know what the material is.... There is a big difference between something that "didn't fail at 3000 psi" and something that is "safe at 3000 psi".... The link lever is a perfect example.... It didn't fail at 3000 psi but did at 4500.... What does that tell you, really?.... Well, using a 3:1 safety margin, it tells you that the lever was safe at 1000 psi but not at 1500 psi.... We use these large safety margins for a reason.... Anything under 2:1 with steel, the part is subject to fatigue shortening its life.... Sharp corners (called stress risers) can make things fail even when calculations tell you they shouldn't.... The material used may not be quite up to spec.... etc.etc.etc….
Large safety margins are there for your safety.... When you test a part to failure, you should not use that part in service unless the load is 1/3 what caused it to fail, or less.... Above all, err on the side of safety, and like always, if you don't know what you are doing around HPA.... don't do it !!!!
Bob
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Thanks Bob. I am not comfortable posting the numbers for unknown alloys. Luckily, there is plenty of metal space to go up in diameter one standard size which immediately buys one more strength, or some stronger alloy can be used. I am hoping that JSAR will make field ready and safe pieces all available. There is a world of difference between "lab" experiments just to test a few things while taking extra safety precautions and walking around the woods with it to your face!
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Here is my tube front now wrapped in Realtree where it sticks out from the stock. The front edge of the wrap wants to bubble just a tiny tiny bit, so I will probably put a thin band of heatshrink around it. Actually, the heat gun might tighten it up there. We will see. It probably doesn't matter because I am good at scraping past all sorts of things in the bush so it likely won't stay pretty for long anyway. ;D
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Bob, one correction is regarding what you wrote about the lever. They are failing at factory 3000 psi from what appears to be from cocking, and may or may not also be from firing it. This has been confirmed by several other posters. The result is the same though, a stronger than factory lever is definitely needed, and I trust that Travis will come through with an offering for one.
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I was referring to the link lever you made.... Yes, I agree that the stock cocking handle appears to be having problems, even at 3000 psi.... I don't know if that is from excessive hammer spring tension, wear, or bending.... but it sure looks like Crosman may have underbuilt that part.... Personally I would use a larger pivot pin, and a much larger cross section on the yoke where that pin goes through, to prevent bending and wear.... It may need a beefier link lever as well, even at 3000 psi, I haven't seen any photos of problems with the stock one (yet)….
Bob
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Ah yes, the link. Yes, that was &^^&. ;D
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Here is the look with the camo wrap added on the tube but without the cutdown bottom rail for others to reference. I will link the wrap I used below. Note that the factory Benjamin Realtree Xtra has a lot more green in it. Personally, I wish the factory one matched the wrap that I used with more brown. There is very little green where I hunt during hunting season, so green is not helping.
Camowraps (RT-CAK6-XT) Xtra Camo Accessory Kit
https://www.amazon.com/dp/B00OB8ESPK (https://www.amazon.com/dp/B00OB8ESPK)
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So...
A couple of questions:
First, is that pin the weakest point?
What's the NEXT weakest point after the pin is fixed?
And the next after that? Lever? Action?
What size would the pin have to be to have the 3 to 1 safety margin?
I don't think you should select for the highest strength steel but instead pick a commonly used good one for your calculation value so it's insurance for a bad batch of the high strength then. Like you are going to use a grade 8 bolt but you calculate for a grade 5 to cover the idiot factor because sooner or later one shows up.
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Cocking handle lever rear main bolt. The threading is only used for retention. The full pin diameter recesses into breach aluminum on the bottom barely by 1 full turn. They really should have counter bored that a bit deeper because this bolt likes to get loose! Please don't let this become too loose.
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Carl, the cocking lever is problematic even at 3000 psi, from the comments and pics in this thread....
Bob
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Lever, pins, and link.
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Bob, now that I have a minute to come back to this... .6 as a tensile to shear criterion is fine. Depending on which industry and criterion is being followed this can wildly vary as you know. I have heard of .5 all the way to .7 being used. I think you are being generous with tensile strength for 1144. I used a lower number, and as we both previously noted, we don't even know if that is what it is. If it is, and not a stronger steel, then I think they may have gone with less than a 3 safety margin, more like 2.5. In reality they probably know from testing or material property the actual shear strength and are not using a ratio of tensile. Like I said, known material needs to be used here. We are just guessing otherwise.
Here is another way to realize the likely strength, from the economic side. This is just a mental exercise, nothing to act on. They want to maximize profits. Stronger or larger than necessary parts reduce profits. You can therefore believe that the 3 to 1 (or even 2.5) safety net is at 3000 psi for all of these parts. That's the profit business as you know. It might be at 3500 if you believe the bean counters mitigated litigation risk for one left in a hot car that also had the cheap gauge off by a few hundred psi. ;) Too much speculation!!!
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Most of the cocking lever problem results from the heavy hammer spring being compressed over and over and it has caused the actual lever to be bent as well. JSAR is developing a lever and dog bone with much more MEAT to it so it shouldnt be and issue either way you use it.
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You should just open me a tab at this point. ;D Can I order one yet?
What do you summarize on the pins, or did you make a test jig and break some? 8)
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You should just open me a tab at this point. ;D Can I order one yet?
What do you summarize on the pins, or did you make a test jig and break some? 8)
Its all in CAD but we can see what loads will be on everything in the program so were good
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You should just open me a tab at this point. ;D Can I order one yet?
What do you summarize on the pins, or did you make a test jig and break some? 8)
Its all in CAD but we can see what loads will be on everything in the program so were good
Put me down as #2 on the list. 😁
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No wonder it looked funny when I typed dovel... ;D
But to the point, this is a good thread for those people without engineering type of thinking.
For most people I don't think that even realize how much there is to consider making a PCP gun.
Just for one cocking lever linkage pin there is safety margins to be considered.
And there is that idiot factor also to think about, someone is bound to pull the trigger with the bolt open.
Just something to think when planning to make a pcp for the first time.
Marko
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let us know when the lever is available, i will take one
before i start cranking the hammer spring !
thanks ;)
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Can forcing slugs that are too tight into the chamber with the lever cause this lever problem?
Roachcreek
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Most of the cocking lever problem results from the heavy hammer spring being compressed over and over and it has caused the actual lever to be bent as well. JSAR is developing a lever and dog bone with much more MEAT to it so it shouldnt be and issue either way you use it.
Also wanting to be on the list...
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David, thanks for catching the error I made on the tensile strength of 1144 Stressproof…. I read the wrong line in a table.... It shows how easy it is to make a mistake.... I corrected the errors in Reply # 278.... :-[
McMaster Carr show a 1/8" hardened alloy steel dowel pin with a "breaking strength" of 2600 lbs.... Something else would undoubtedly fail first, most likely the cocking lever hole that the pin passes through, or the link lever.... ;)
As Marco says, some idiot will eventually fire the gun with the bolt open, and all the calculations in the world cannot deal with that.... >:(
Bob
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David, thanks for catching the error I made on the tensile strength of 1144 Stressproof…. I read the wrong line in a table.... It shows how easy it is to make a mistake.... I corrected the errors in Reply # 278.... :-[
McMaster Carr show a 1/8" hardened alloy steel dowel pin with a "breaking strength" of 2600 lbs.... Something else would undoubtedly fail first, most likely the cocking lever hole that the pin passes through, or the link lever.... ;)
As Marco says, some idiot will eventually fire the gun with the bolt open, and all the calculations in the world cannot deal with that.... >:(
Bob
No worries Bob. You did have me scratching my head and cross checking different tables. I see 104 to 115 listed, depending on the source. As you see, as that is marginal, it is likely (hopefully) a stronger hardened steel, but we don't know.
Travis, I hope you please overengineer the parts. Spec it for 5000 and 100% helium, not to endorse it as such, but just for the extra safety margin and gun durability. Someone should be able to pick it up after 10 years of use and not worry about it. I am sure the extra 20 dollars or whatever won't be minded by those who are anyway spending so much to soup up their Bulldog. I know things like grade 8 steel alloy dowel pins can be 15 dollars each, but at least for myself, would welcome the extra durability.
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@PCPhack
Got my SS valve in today ( QUICK shipping from JSAR and during the holidays too!) and wanted to ask you where you sourced the .015 jet. I went to both Auto(ripoff)zone, O'Riley's and Advance Auto parts with the 'OEM' SS jet and asked for the .015 you described in an earlier post and they all just we're blank... They can "look it up if you tell them what car it fits" but have no way in their computers just for parts... dumb programming and over reliance on computers. Just knownothing kids behind the counters.
It can be looked up if they have a part number but they don't have a jet size list EITHER!
Looked on Internet and places like Amazon and I generally have good search-fu but skunked out.
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Motorcycle shops man!
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Set of jet drills and solder. https://www.amazon.com/Micro-Drill-0-013-0-079-0-4-2mm/dp/B001IC9CXK/ref=sr_1_16?ie=UTF8&qid=1546292241&sr=8-16&keywords=jet+drills (https://www.amazon.com/Micro-Drill-0-013-0-079-0-4-2mm/dp/B001IC9CXK/ref=sr_1_16?ie=UTF8&qid=1546292241&sr=8-16&keywords=jet+drills)
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Set of jet drills and solder. https://www.amazon.com/Micro-Drill-0-013-0-079-0-4-2mm/dp/B001IC9CXK/ref=sr_1_16?ie=UTF8&qid=1546292241&sr=8-16&keywords=jet+drills (https://www.amazon.com/Micro-Drill-0-013-0-079-0-4-2mm/dp/B001IC9CXK/ref=sr_1_16?ie=UTF8&qid=1546292241&sr=8-16&keywords=jet+drills)
Thanks!
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Yep, solder the end up and then drill it to the size you want. I initially used a needle, but then got these bits. Just convert from mm, as we are talking about inches (mils) on these jet sizes, if you buy a metric set.
UEB Mini twist drill Bit Kit, 0.4mm-3.2 HSS Micro Precision Twist Drill 150Pcs with Carry Case for PCB Crafts Jewelry Drilling Tool https://www.amazon.com/dp/B01M99N1BA/ (https://www.amazon.com/dp/B01M99N1BA/)
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Factory dogbone link for reference. It is also ferrous/sticks readily to a magnet.
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David, to do a "column buckling" analysis, you also need the length between the load points.... That should be between the holes at the sides closest to each other.... It looks like the pins on both ends are the same size (1/8") ???
Bob
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Set of jet drills and solder. https://www.amazon.com/Micro-Drill-0-013-0-079-0-4-2mm/dp/B001IC9CXK/ref=sr_1_16?ie=UTF8&qid=1546292241&sr=8-16&keywords=jet+drills (https://www.amazon.com/Micro-Drill-0-013-0-079-0-4-2mm/dp/B001IC9CXK/ref=sr_1_16?ie=UTF8&qid=1546292241&sr=8-16&keywords=jet+drills)
+ Thanks
I hate a growing monopoly but have to love Amazon: Ordered for Wednesday delivery. Actually ordered both sets posted by OldPro and PCPhack as I'm sure I need them somewhere :D
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David, to do a "column buckling" analysis, you also need the length between the load points.... That should be between the holes at the sides closest to each other.... It looks like the pins on both ends are the same size (1/8") ???
Bob
Thought I posted it. Hmm. 1.23 inches, closest 2 points.
Happy New Year!
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I used a "column buckling" calculator and got a maximum supported load of 798 lbs for a "pinned" column.... so that works out to a safety margin of about 2.7 at 3000 psi, or only about 1.8:1 at 4500 psi, using mild steel for the material for the link.... IMO that means the factory link should not be used above the 3000 psi recommended pressure....
I don't know how your longer link compared in thickness, however....
Bob
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The longer one was just to test a bit. It's in the trash already.
I don't want to guess on metal Benjamin used, but either they are OK with lower safety margins, or the guesses here on steel type are wrong. Like before, for economic reasons, you are likely right. Perhaps after I get my hands on some heavier duty parts from JSAR, we can do some tests to better determine metal type of these factory ones.
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Just to break it up a bit................
Happy New Years!!!!!
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Happy New Year!!! Lol @ Loosy Moosy. Ughhhh, why do I know that. ;D ;D
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Happy New Year!!! Lol @ Loosy Moosy. Ughhhh, why do I know that. ;D ;D
LMBO!!!! Who knew right?!!!!
Been doing some shop work for the linkage issues, figured tonight would be a good break!!!
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Just to break it up a bit................
Happy New Years!!!!!
AAAHHHHHGGUUUUHHHHH!!!!!!!!!
MONSTER!!!!!!! BIGFOOT!
{What? No copied PIC?}
You need some HUNTER SAFETY ORANGE, you could get shot, haha
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"That dang Samsquanch!!!!!"
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To complete the documentation... here is the front dogbone link pin. This looks like a typical industrial steel dowel, complete with beveled end, ferrous, etc.
.125 inch diameter
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I don't know if any of you have been following my thread on the Darkside about Chairgun and Strelok Pro but Igor/Strelok has added drag functions: GA (pellets), GL (blunt like pistol bullets) and GS (round ball) for me.
Talked to him about Airguns vs PB needs yesterday and it updated today, he's quick!
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NICE !!!....
Bob
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Nice! That's in the payed version though not free? Might have to invest
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Nice! That's in the payed version though not free? Might have to invest
I have the paid version which is cheap for what you get, don't know if he'll put it in the free.
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Fire lapping is done! It was quite a bit of effort, so I hope it pays off. It was like putting dirt in my barrel on that first grit especially. :D The kit was supposed to come with application plates, but it did not. I used a pair of machinist parallels to do it (flat and long) and then cleaned them up afterwards.
I did the following, using 4 different slug designs with each grit below
-Cleaned barrel, 20 patches
-16 shots - 220 grit
-Cleaned barrel, 20 patches
-20 shots - 330 grit
-Cleaned barrel, 20 patches
-25 shots - 600 grit
-Cleaned barrel, 20 patches
-Bore paste swabbing, several times
-Cleaned barrel, 20 patches
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{Jumping up and down in excited impatience, haha}
How does it look?
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No borescope here, but with the naked eye....very shiny. :D :D
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I have done several barrels over the years, best improvement was that it was easier to clean the lead out.
Roachcreek
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>:( :D
Well now it is a case of hurry up and wait.
I wanted to see the results of the higher power and the barrel lapping. The weather is nasty, cold and misting. I also only had about 20 minutes. Then during this group, I also noticed the valve was leaking into the barrel between shots. I am not sure why it suddenly decided to do that, as it has been sealing up fine for hundreds of shots. Maybe some of the lapping compound got in it. Who knows. It was not a good group overall, I believe due to the leak, and me hurrying, but look at how close side to side they are. Perhaps the vertical gap was due to the leak. I have had groups at this distance that are one coin sized hole earlier at lower power, but the left to right distance was twice this, so I need to sort out the vertical gap.
Earlier the gun was shooting 1.5 to 2 MOA at 100 yards. I hope it can shoot even better than that after sorting this out. As of now I can't even hunt with it at my typical 75 yards.
Another potential issue was that this time I had the DonnyFl Emperor on it, while my earlier groups were with the Pitbull moderator or no moderator. I believe the DonnyFl threaded end can move too much as it doesn't insert very far to the shroud. Too many variables here....bit of a rant. Time to fix the leak and regroup (literally).
178gr NSA
880fps
45 yards
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Don’t forget the very first group might not be the best after a cleaning. Fix the leak, check velocity ES and run 20 more bullets through it and see it that helps. Also, don’t forget the increased power shifts the harmonics of the barrel. Sometimes for the better, other times for the worse. Keep at it. You’ll get her dialed in.
Peter
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Don’t forget the very first group might not be the best after a cleaning. Fix the leak, check velocity ES and run 20 more bullets through it and see it that helps. Also, don’t forget the increased power shifts the harmonics of the barrel. Sometimes for the better, other times for the worse. Keep at it. You’ll get her dialed in.
Peter
Thanks. Yes, I have noticed the pattern. After every round of modifications I have bad groups. Then I spend a bit more time tweaking, and the groups close up. Then I hunt, have success, and finally tear it apart again. Lol. Hopefully I reach the point of just leaving it alone soon and calling it done. I did run around 20 slugs through it, but with many variables at play, I just need to go back a bit and try again. Indeed the harmonics may be an issue, and at such a cranked up power level, there is a lot more to tame than factory.
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Don’t forget the very first group might not be the best after a cleaning. Fix the leak, check velocity ES and run 20 more bullets through it and see it that helps. Also, don’t forget the increased power shifts the harmonics of the barrel. Sometimes for the better, other times for the worse. Keep at it. You’ll get her dialed in.
Peter
Thanks. Yes, I have noticed the pattern. After every round of modifications I have bad groups. Then I spend a bit more time tweaking, and the groups close up. Then I hunt, have success, and finally tear it apart again. Lol. Hopefully I reach the point of just leaving it alone soon and calling it done.
Lol. That’s just the problem with us tinkerers. We never leave we’ll enough alone. 8)
Peter
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Tore it apart. A look down the barrel...
The second picture is showing reflections of things in the garage.
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Dirty poppet boy. I knew it.
I thought I cleaned it up pretty well, but it is amazing where stuff can migrate to even when the air is blowing out. It was probably from the lapping compounds. I will stop here tonight.
I also noticed that the top of the bolt cup for the airflow is nicking my oring, as I run a stiffer than oem oring in the barrel. So I will take it the rest of the way apart and smooth that sharp edge. While at it, everything will get a bath, and fresh Krytox to the valve innards.
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I cleaned every last part in the rifle now with alcohol and reassembled it. It was very time consuming as I removed all lubricants and kept cleaning until swabs came away clean. I gave the block a bath in it, and went through a few dozen super cheap throw away tooth brushes. Having read the advice of several in other threads about bolt and hammer area lubbricants, specifically to not use any, I didn't use any Moly this time either as I normally have. The cocking is far harder now and I can't believe that it wouldn't wear down the receiver aluminum if I leave it like this long term. So I will need to choose some kind of lubricant, at least for the bolt/lever area.
I took the jet out just to try it this way for a while and see the higher power. I filled to 4500 and shot a 142gr NSA. This made 360 fpe at 1069 fps. I will do a 178 gr next time, as this might get near 400 fpe.
I then retuned for lower pressure and shooting the 178gr NSA at 934 fps for 345 fpe. I will hunt with that tomorrow night and Friday morning.
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360FPE is smoking!!! Great job!
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That's awesome David! And please keep sharing all that you do!
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Thanks guys. I made that much power before with the full factory spring and 300 psi less pressure. My spring has 2 loops cut off now. I might get a new factory spring at some point, just to see what it can do.
I really wish Nielsen Specialty Ammo made a slug around 160gr that would still fit the factory magazine. There are some brands out there at that weight, but they were not very accurate, and not nearly as good ammo quality as NSA is turning out.
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Try Richard Krebb's "ANVIL" 150 gr at Hikalbigbore.com. That thing is amazing with the bulldog. I get the best results with 358 sized.
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I will have to try those at some point. I also just remembered that I have some Mr. Hollowpoint 165gr to try out, although I am pretty sure they won't fit the magazine either.
Right now I am letting the rifle sit. I know it has stiction with this kind of tune. I was able to anticipate it before and exactly compensate for the fps loss with about 150 psi more pressure. So I will let it sit an hour, and take a shot at the higher pressure to see if I am still at 934 fps and adjust accordingly. I am looking forward to the 2nd generation SS valve that Travis is working on, to be rid of the stiction.
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The 165 gr hollow points fit in the magazine.Thats an awsome bulldog you have,i cant wait to get the jefferson state stuff for mine.thanks for posting all your hard work. eric
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It would be an interesting test series to try to see how long it takes for it to appear. Try it one hour since the last shot/valve cycle, then two hours, four, six, ...
I wonder, if it takes a couple hours if a 'blank' shot without a bullet would reset the clock on the valve. Before you go out hunting, fire a shot so when you need it after a while, it's OK. Kind of like we do when shooting the Holy Black Powder, because the rifles first shot is different from following shots we fire a fouling shot first.
Travis said not to dry fire it but that means without air, right? Wondering if it is OK to shoot with air but no bullet to stop the stiction for a while. Do it before you leave n go out.
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It would be an interesting test series to try to see how long it takes for it to appear. Try it one hour since the last shot/valve cycle, then two hours, four, six, ...
I wonder, if it takes a couple hours if a 'blank' shot without a bullet would reset the clock on the valve. Before you go out hunting, fire a shot so when you need it after a while, it's OK. Kind of like we do when shooting the Holy Black Powder, because the rifles first shot is different from following shots we fire a fouling shot first.
Travis said not to dry fire it but that means without air, right? Wondering if it is OK to shoot with air but no bullet to stop the stiction for a while. Do it before you leave n go out.
With air but no bullet is ok, but I generally try to avoid it.
I will not need to cycle it after leaving camp though and hopefully taking a hunting shot 1 or 2 hours later, as I finished the test. Stiction shows up within 45 minutes (shortest test time I did) and is the same after a few hours. This is consistent with what I have seen before. My hunting tune point is 150 psi more pressure and 1 more turn of the hammer spring from my 934 fps tune. This gives me a stiction shot that is within 5 fps of my 934 fps tune a few posts up, and where I will zero the scope tomorrow while tethered to a bottle. After that I will be ready for the two hunts. This is one way that I have worked around stiction and is the way that keeps the most power. The other way is a small jet and more hammer, but then the valve makes a bit less power.
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I am short on time to pack up and head out hunting today. I zeroed the rifle quickly and then shot 2 groups. One at 40 yards, single hole!!! Then I shot this one at 75 yards. I could have adjusted the scope a hair more, but called it good. This is the best group so far and I was not taking my time! I really wanted to hang out to shoot more groups, but that will have to wait. I have the Pitbull moderator back on also.
NSA 178gr. 935 fps. 345 fpe.
75 yards
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JSAR just listed a new heavy duty charge handle for the Bulldog!
http://www.jsairrifles.com/Benjamin-Bulldog-Reinforced-Charge-Handle_p_148.html (http://www.jsairrifles.com/Benjamin-Bulldog-Reinforced-Charge-Handle_p_148.html)
Putting in my order!
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Levers are done
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Levers are done
THANK YOU!
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Pitbull Airguns has them up for pre-order. They are going through coating right no
https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle (https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle)
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Great work, both vendors. I am sure it is no coincidence that both levers were posted up the same day.
Now, do either of them have a longer nub where the linkage attaches, so that the bolt retracts a tiny bit more than factory?
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Look at where we beefed it up no nub just solid alloy.
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Travis, I think what he is asking is if you made any geometric changes in the dimensions to change the movement lengths (ie: how deep the bullet seats then how far the bolt retracts) or is it dimensionally identical to the factory part
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Travis, I think what he is asking is if you made any geometric changes in the dimensions to change the movement lengths (ie: how deep the bullet seats then how far the bolt retracts) or is it dimensionally identical to the factory part
This is correct. I hoped when Travis wrote earlier that he was listening to the requests, he would pick that feature up. It would gain a few fps. I am guessing that since most people don't go quite as large on the porting they would not see the benefit, so they didn't extend it out further. If so, I can't tell from the picture.
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No luck hunting. We have an extended deer season here for doe and antlerless deer. I saw 7 doe last night, but our host asked us not to take any. This morning I saw a buck, but not legal. We didn't see any hogs. The 178gr NSA slugs will have to wait.
I hope to reshoot the various NSA slugs and a few others soon to compare groups now that I have it shooting so accurately with the 178gr (higher power tune, lapped barrel, and Pitbull moderator back on).
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Look at where we beefed it up no nub just solid alloy.
Travis, I've gotta say that it's an awesome work of engineering on top of using a superior alloy! And we shouldn't overlook "The main pivot also has a pressed in self lubricating bronze bushing for longevity."
Thank you Travis & JSAR!
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Pitbull Airguns has them up for pre-order. They are going through coating right no
https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle (https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle)
And I have to say Thank You to you too Matt! Having a second alternative for the inherently weak factory piece in steel is awesome! I'm very happy that Pitbull and JSAR are offering more options for Bulldog owners to maintain and improve our rifles!
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Pitbull Airguns has them up for pre-order. They are going through coating right no
https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle (https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle)
And I have to say Thank You to you too Matt! Having a second alternative for the inherently weak factory piece in steel is awesome! I'm very happy that Pitbull and JSAR are offering more options for Bulldog owners to maintain and improve our rifles!
No problem. I just don't have the equipment the businesses do or I would have done them myself. Whatever I guess. The marketing world is not for the little man. At least someone acknowledges who came up with the idea. lol ;D
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Pitbull Airguns has them up for pre-order. They are going through coating right no
https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle (https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle)
And I have to say Thank You to you too Matt! Having a second alternative for the inherently weak factory piece in steel is awesome! I'm very happy that Pitbull and JSAR are offering more options for Bulldog owners to maintain and improve our rifles!
No problem. I just don't have the equipment the businesses do or I would have done them myself. Whatever I guess. The marketing world is not for the little man. At least someone acknowledges who came up with the idea. lol ;D
And not to forget the man who sent me my first new custom steel charging handle that should last through another shooting season and more! ShakySarge came to my rescue long before anyone brought a replacement to market!
Have you had an opportunity to use the new factory replacement handle as a template yet?
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Pitbull Airguns has them up for pre-order. They are going through coating right no
https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle (https://www.pitbullairguns.com/product-page/cocker-spaniel-steel-charging-handle)
And I have to say Thank You to you too Matt! Having a second alternative for the inherently weak factory piece in steel is awesome! I'm very happy that Pitbull and JSAR are offering more options for Bulldog owners to maintain and improve our rifles!
No problem. I just don't have the equipment the businesses do or I would have done them myself. Whatever I guess. The marketing world is not for the little man. At least someone acknowledges who came up with the idea. lol ;D
And not to forget the man who sent me my first new custom steel charging handle that should last through another shooting season and more! ShakySarge came to my rescue long before anyone brought a replacement to market!
Have you had an opportunity to use the new factory replacement handle as a template yet?
I have a couple different templates drawn out that I used it for so far. Just have not had the weather to use them while shooting. Messed with moving the linkage holes in a couple different directions to further seat the bullet/pellet with larger porting. Time will tell I suppose.
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My hats off to ShakySarge for taking care of us when we needed something better you did a great job Sarge thanks for get me one so quickly it works great. Thanks Terry
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My hats off to ShakySarge for taking care of us when we needed something better you did a great job Sarge thanks for get me one so quickly it works great. Thanks Terry
No problem, I enjoyed it while it lasted! I appreciate the thanks.
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Yes, thanks for the one you made for me, it was a good trade!
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Yes, thanks for the one you made for me, it was a good trade!
You're quite welcome! I just want some decent weather to shoot those slugs!
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^^^ thatsa fact.... ;D
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Was the idea elsewhere before this thread? Just curious if there is other Bulldog activity that I am not aware of.
Edit: Nevermind, I realize you meant Matt, who indeed made the first ones by hand and very fast after the issue was documented here and confirmed by others. I had mine within a week!
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Tip: Bulldog trigger pin replacement
The Bulldog trigger hinge dowel pin is very easy to lose. If you lose it, and need a quick replacement, dremel bit shanks are the correct diameter. Pick an old bit, and cut a piece of its shank off to use as your new trigger hinge. This part is not under any particular stress, so it will suffice.
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Was the idea elsewhere before this thread? Just curious if there is other Bulldog activity that I am not aware of.
Edit: Nevermind, I realize you meant Matt, who indeed made the first ones by hand and very fast after the issue was documented here and confirmed by others. I had mine within a week!
Actually I called Matt at Pitbull on January 2 and asked him if he was reading this thread and what would he think of making a stronger handle for his Pitbulls because there was a need.
Simultaneously, Travis also saw a need and filled it.
This was QUICK WORK from both! Capitalism in action! Competition creates better products!
(But but before that I had ShakySarge make me one of his hand made ones to use to give credit there)
And now we will see which stands up... the steel one or the aluminum MkII one!
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Ah, OK, now I get it. It's nice to hear the backstory, and it's great to have choices on the upgrades.
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I know 7075 is stronger, but I am curious how the linkage dowel hole will hold up on the JSAR one, as that is where my oem one wore out, not on the bolt hole at the back. The rest of it looks strengthened by both physical sizing and the stronger 7075, but the metal between the linkage hole and the edge looks about the same as oem, leaving only the stronger alloy there as the improvement.
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Was the idea elsewhere before this thread? Just curious if there is other Bulldog activity that I am not aware of.
Edit: Nevermind, I realize you meant Matt, who indeed made the first ones by hand and very fast after the issue was documented here and confirmed by others. I had mine within a week!
Actually I called Matt at Pitbull on January 2 and asked him if he was reading this thread and what would he think of making a stronger handle for his Pitbulls because there was a need.
Simultaneously, Travis also saw a need and filled it.
This was QUICK WORK from both! Capitalism in action! Competition creates better products!
(But but before that I had ShakySarge make me one of his hand made ones to use to give credit there)
And now we will see which stands up... the steel one or the aluminum MkII one!
Firstly, no one "had" me make anything. As a bulldog owner I recognized the necessity for a stronger lever and came up with the solution myself. Sadly, I made the mistake of sharing that information in the thread, which will not happen again.
Spent hours upon hours figuring out what to use and then did so. Secondly, if my mind doesn't phase me, I sent most of them out for free save yours that went out in exchange for some cast slugs, which, I am not going to turn down when offered.
Lastly, both aftermarket levers came solely from my hand made levers and to charge 50 a piece is more than absurd especially when using mills instead of doing the work by hand. At the most, I charged 20 bucks shipped. Guess we know who takes advantage of folks and who doesn't don't we?
Anyways, I am already addressing other issues and resolutions with the levers to allow further seating of cast slugs with an oversized port. You can rest assured this information will not be revealed in any thread again.
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Was the idea elsewhere before this thread? Just curious if there is other Bulldog activity that I am not aware of.
Edit: Nevermind, I realize you meant Matt, who indeed made the first ones by hand and very fast after the issue was documented here and confirmed by others. I had mine within a week!
Actually I called Matt at Pitbull on January 2 and asked him if he was reading this thread and what would he think of making a stronger handle for his Pitbulls because there was a need.
Simultaneously, Travis also saw a need and filled it.
This was QUICK WORK from both! Capitalism in action! Competition creates better products!
(But but before that I had ShakySarge make me one of his hand made ones to use to give credit there)
And now we will see which stands up... the steel one or the aluminum MkII one!
Firstly, no one "had" me make anything. As a bulldog owner I recognized the necessity for a stronger lever and came up with the solution myself. Sadly, I made the mistake of sharing that information in the thread, which will not happen again.
Spent hours upon hours figuring out what to use and then did so. Secondly, if my mind doesn't phase me, I sent most of them out for free save yours that went out in exchange for some cast slugs, which, I am not going to turn down when offered.
Lastly, both aftermarket levers came solely from my hand made levers and to charge 50 a piece is more than absurd especially when using mills instead of doing the work by hand. At the most, I charged 20 bucks shipped. Guess we know who takes advantage of folks and who doesn't don't we?
Anyways, I am already addressing other issues and resolutions with the levers to allow further seating of cast slugs with an oversized port. You can rest assured this information will not be revealed in any thread again.
Sorry, that was a misworded sentence and I apologise for the misunderstanding. I did not reread and notice then correct how it read after typing it because that's certainly not what I meant.
I always try to give fair value and don't take from others unless the scales balance and everybody wins. I thought we made a good deal and both gained value.
Ment to say
(But before that I have one ShakySarge made for me, one of his hand made ones to use to give credit there)
That post was typed on my phone instead of my PC as I usually do and I was fighting the autocorrect.
Note that to me it was more valuable because you worked hard to 'hand make' a piece of craftsmanship vs just turning wheels on a mill. It was supposed to be a compliment.
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Was the idea elsewhere before this thread? Just curious if there is other Bulldog activity that I am not aware of.
Edit: Nevermind, I realize you meant Matt, who indeed made the first ones by hand and very fast after the issue was documented here and confirmed by others. I had mine within a week!
Actually I called Matt at Pitbull on January 2 and asked him if he was reading this thread and what would he think of making a stronger handle for his Pitbulls because there was a need.
Simultaneously, Travis also saw a need and filled it.
This was QUICK WORK from both! Capitalism in action! Competition creates better products!
(But but before that I had ShakySarge make me one of his hand made ones to use to give credit there)
And now we will see which stands up... the steel one or the aluminum MkII one!
Firstly, no one "had" me make anything. As a bulldog owner I recognized the necessity for a stronger lever and came up with the solution myself. Sadly, I made the mistake of sharing that information in the thread, which will not happen again.
Spent hours upon hours figuring out what to use and then did so. Secondly, if my mind doesn't phase me, I sent most of them out for free save yours that went out in exchange for some cast slugs, which, I am not going to turn down when offered.
Lastly, both aftermarket levers came solely from my hand made levers and to charge 50 a piece is more than absurd especially when using mills instead of doing the work by hand. At the most, I charged 20 bucks shipped. Guess we know who takes advantage of folks and who doesn't don't we?
Anyways, I am already addressing other issues and resolutions with the levers to allow further seating of cast slugs with an oversized port. You can rest assured this information will not be revealed in any thread again.
Sorry, that was a misworded sentence and I apologise for the misunderstanding. I did not reread and notice then correct how it read after typing it because that's certainly not what I meant.
I always try to give fair value and don't take from others unless the scales balance and everybody wins. I thought we made a good deal and both gained value.
Ment to say
(But before that I have one ShakySarge made for me, one of his hand made ones to use to give credit there)
That post was typed on my phone instead of my PC as I usually do and I was fighting the autocorrect.
No worries. I don't take things literally, but am a bit blunt at my rebuttals. Hopefully this garbage weather clears up and I can get back out and do some more testing with the slugs and some other items. Having no heat in the shop is no good!
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Glad that worked out...Hate to see a great thread go south for a misunderstanding. All part of what makes the GTA the finest airgun forum on the net!
pv
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David, how was your hunting trip?
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It was relaxing, but didn't see any hogs. We saw some doe, but didn't harvest any (at hosts request). We saw 1 buck, but he wasn't legal. If it was my lease we would have taken a doe, but considering all I paid was gas, I can't complain. :D It's nice to see the animals anyway.
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Just getting out can be quite nice!
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The 165 gr hollow points fit in the magazine.Thats an awsome bulldog you have,i cant wait to get the jefferson state stuff for mine.thanks for posting all your hard work. eric
Thanks Eric.
I did have a chance to try the Mr. Hollowpoint 165gr fit to the magazine, and you were right. To my surprise, they do fit just fine. I hope to get out in the next days to freshly compare several slug groups now that my Bulldog barrel has been lapped and I am shooting up at 345 fpe.
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The i Lyman/Ideal moold # 358429, casts at 178 with 40-1a and just fits the magazine.
Not all the generations of the mild are the same, but my 35 dollar mold sure works, and in duct seal it expands back Into itself with my ported Bulldog. At 15 yards, it is a one hole even with my poor eyesight, and I have recovered thefused together in one massive lump/
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Thanks Lani. I need to check out casting one day.
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I thought that I had time to shoot tonight, but in only 1 week of sitting, it leaked out and the JSAR valve is now frozen with the poppet in the plunged position. I am not able to refill it even if I cock it and take all hammer tension off the valve. This is very annoying and the second time this has happened. So instead of going shooting tonight, I get to tear the gun down again. I don't get why it gets stuck plunged since there is a valve return spring. Last time I even spun the poppet stem in the press to lightly sand it with wet/dry high grit sandpaper to smooth it and allow it to move a bit better since it was actually too tight before. From now on I will store it with no hammer spring in it or back it all the way out and see if that helps.
I also need to figure out where it leaked from, the poppet at the seat or some oring. It was fine over the course of a few days a week ago and I did not see a leak then. It must be very slow or it let loose at some point over the last week.
>:( >:( >:(
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I took the rifle apart to diagnose and found the poppet broken. The rifle was never dry fired. I have to wonder if the material is strong enough for the higher pressure. The poppet slid right out with the valve, so the stem was not stuck in the gun like last time, so this is a completely new failure mode. It shot groups and some test shots hunting last week just fine. :(
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For a poppet to be reliable with those high pressures, it must be built/designed for it and the JSAR valve was only designed for a 3K fill. Perhaps JSAR will have an answer. If one provides the higher pressure tubes, one should provide a higher pressure poppet. Not a hit on them, just an observation as a 1500PSI increase is quite substantial.
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Yeah. I have shot it maybe 5 or 6 times up near 4500, and the rest at 4000 since getting the titanium tube. My hunting and bottled shooting tune is at 4000.
It was around 3800 when I put it away. When I came back it was empty and this poppet was broken. I did flow some air through it when it was leaking and I was trying to refill it, so I guess there is a chance that it was stuck and the filling attempt somehow broke it.
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Yeah. I have shot it maybe 5 or 6 times up near 4500, and the rest at 4000 since getting the titanium tube. My hunting and bottled shooting tune is at 4000.
I am inclined to believe that is what wrecked the poppet. Are they made of peek or delrin for the JSAR valve, looks to be delrin. Even a 1Kpsi increase is substantial honestly. I have no doubt that a LOT more can be gotten out of the factory valves as well as the JSAR valves if the poppet was peek and the intake from tube to valve was bored out a bit larger with a poppet that had it's stem thinner at the base than the end. I did my poppet in such a manner and gained about 65FPS. Just saying.
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I had a chat with Matt. He asked me to contact Jacob next week after he and Travis are back from Shot Show to fix me up. They are working on new internals soon, but hopefully I can get a spare original one quickly in the meantime.
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Good deal. Hope you get it sorted out quickly. I absolutely HATE when my go to shooter is down! I feel your pain.
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I've got my SS valve installed in my Pitbull but after chatting with Travis on the phone about springs n jets he recommended shooting / filling to just 3400 max (stock tube too).
I had chronyed the provided SS hammer spring and was not getting what I wanted but he said for the higher fill use the factory spring with 2 coils cut off. Maybe he was hinting without actually saying that the valve had a max?
Also, I'm going to try using a thinner cross section o-ring and backup rings to see what that does on first shot issues.
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I run the stock spring with 2 coils cut off, and have plenty of spring up at 4k psi. I am voting for fluke breakage until I see it happen twice. If it happens again, the poppet isn't strong enough. I am not sure what the current material is, peek, delrin, or something else. I am guessing that Travis will have an expert opinion, but no way would I bug him at Shot Show about it. Now I just have to keep my buy finger away from that 452 Slayer in the meantime. Lol. Actually, I should go back to work on my Brod 257 project.
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I think I will keep my pressure around 3400 psi max with my JSAR valve and tube, when it finally gets anodized. I want to keep it at where we would be pushing it with a oem tube just a bit too far, but using the JSAR tube instead.
Looks like anything higher will get expensive.
But then I did not have the installation problems David had, mine was too tight, I spun it with a very high grit paper for just a few seconds and it went right in. I bought a spare lever but I don’t have any wear or slop in mineafter maybe 150-200 shots with the 178’s and 60,or so with the 120,.
Being a long time caster and shooter of cast bullets, and shooting many deer and 6 elk with them, and fan of Elmer Keith, if I can move my 178 bullets mentioned above a speed you would get out of a k frame 4 inch Smith, 860 FPS, without shooting that k frame used as a benchmark loose, I will be content. And the 120’s I cast at what would be a starter load to medium load from a 9mm will do me just fine.
If I want it any hotter I will lay it on the pavement on a July afternoon.
This thread has been a education for me while I wait for that tube, however as we seeing,education does not come cheap.
Roachcreek
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Yeah, it's sort of pay to play. At least everyone else can benefit from my success and failures since they are all here. My Bulldog probably has 600 shots through it or something like that, and as many shots tuning or otherwise fiddling, as actually shooting. ;D
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Absolutely David and thank you for pioneering for us, or at least for me.
Roachcreek
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Small update: JSAR is sending me a new poppet and I am sending them the broken one for a post mortem exam. Fun times will continue after I receive the replacement one and rebuild the rifle.
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I figured they would, that’s who and what they are, I got the email yesterday that they shipped my tube after anodizing it.
Roachcreek
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PCPHach: Pushing back the boundaries of the envelope!
Thanks. 😁
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Absolutely David and thank you for pioneering for us, or at least for me.
Roachcreek
I have to agree, thank you David
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I took the rifle apart to diagnose and found the poppet broken. The rifle was never dry fired. I have to wonder if the material is strong enough for the higher pressure. The poppet slid right out with the valve, so the stem was not stuck in the gun like last time, so this is a completely new failure mode. It shot groups and some test shots hunting last week just fine. :(
By the looks of it its POM, looking at the fracture, I'm just guessing here so don't take my word for it.
But good to hear jsar has you covered.
Have seen identical failures happen when I used POM on my valves before switching to PEEK.
Marko
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I am hoping that we can get JSAR to make the v2 of the Bulldog poppet from PEEK, assuming the current one is POM/Delrin or similar. 50% greater tensile strength and a bit higher rating across several other engineering specifications would be good for these higher power builds.
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I did receive my replacement poppet a few days ago, but haven't had time to rebuild the rifle. I hope to do so in the coming days to finally reshoot several slugs sizes to test accuracy at a full 100 yards. The goal is a 1 inch group at 100 yards.
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Yeah. I have shot it maybe 5 or 6 times up near 4500, and the rest at 4000 since getting the titanium tube. My hunting and bottled shooting tune is at 4000.
I am inclined to believe that is what wrecked the poppet. Are they made of peek or delrin for the JSAR valve, looks to be delrin. Even a 1Kpsi increase is substantial honestly. I have no doubt that a LOT more can be gotten out of the factory valves as well as the JSAR valves if the poppet was peek and the intake from tube to valve was bored out a bit larger with a poppet that had it's stem thinner at the base than the end. I did my poppet in such a manner and gained about 65FPS. Just saying.
Yes, they are Delrin.
Mike
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I have the Bulldog back together. The new poppet with new orings is like a whole new valve and my shot to shot ES is not as tight as before. I also cleaned the barrel, so I am running 2 or 3 dozen slugs through to break it all in again. If this was a small bore, I would put more than that through, but it's a bit wasteful on the big bore.
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Getting serious now. Lol.
;D
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Now you're talkin'.... 8)
Bob
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My JSAR tube had to be sent back.
One end would not allow either the end cap or the valve retainer that came with the JSAR valve to screw in, the other end was ok.
I contacted JSAR and they said to send it back with both end pieces and they would fit it correctly, so it is on its way to JSAR.
Roachcreek
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Sorry to hear that Lani. I am positive that JSAR will sort it out for you.
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Well, one good thing Charlie, JSA is so close to us that the freight is cheap and fast. Regards, Tom
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I have no doubt that they will, and your right Tom, it is really nice to have a company that sells the products they do and offers the services they do so close by.
Now if PA will get my Skyhawk in and forward it to me.
Roachcreek
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Looking at the Pic, I think I Would use Peek, an move the o ring groove back at least 100 tho. ;)
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The new poppet has been holding air fine so far. Will test the valve operation again tomorrow. If all is well, I will go test the various slugs at the range at 100 yards and 350 fpe. Fingers crossed for 1 MOA.
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I can't believe it. The gun sat for 6 days motionless and holding pressure at exactly 4000 psi with no loss whatsoever. Today, now 7 days after putting the new poppet in, I was going to take it to the range. I looked at it this morning and it has no pressure. Something gave way since my post yesterday. It has not been fired or touched for a week. So I tried to pressurize it, and air is leaking from the valve. I suspect the poppet broke again, but will need to tear it down to find out.
The JSAR SS Bulldog v1 valve doesn't appear to be able to handle 4000 psi. This one was never exposed to more than 4000 psi. I will post pictures after tearing it down. Hopefully this can be remedied in v2.
If you have the titanium tube and use higher pressures, along with the SS valve, I highly advise you to store it at under 3k psi, until this is sorted out. You should never store a gun loaded, but in this case I would also say do not load ammunition until the moment you are about to fire, and once you load one, you must safely get rid of it before moving the rifle. This is a real safety issue!
>:(
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That is interesting.
I had my Bulldog filled to 3500 since getting the JSAR valve back in November. I have shot it at the range with 123 grain bullets and at home without bullets held against a rolled sleeping bag to test function after reading about your valve problem. When I got my valve the stem would not enter the raceway, so I spun it for just a few seconds against very fine sandpaper, 600 grit I believe, it is snug enough that when I disambled it to put on the ti tube, the valve pulls apart and the stem stays in the raceway. Each time I shot it, I went down to 2500 psi, it has never leaked.
Perhaps the best pressure is between your 4000 and my 3500 psi.
Roachcreek
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I have confirmed the weakness. See the attached picture. The last one cracked at the smaller oring. This one cracked by the larger oring.
Please use PEEK for v2, and also move the oring groove back Travis!
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Peek won’t seal but the gen 2 version is much stronger for those wanting to use 4000 plus psi.
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Was the idea elsewhere before this thread? Just curious if there is other Bulldog activity that I am not aware of.
Edit: Nevermind, I realize you meant Matt, who indeed made the first ones by hand and very fast after the issue was documented here and confirmed by others. I had mine within a week!
Actually I called Matt at Pitbull on January 2 and asked him if he was reading this thread and what would he think of making a stronger handle for his Pitbulls because there was a need.
Simultaneously, Travis also saw a need and filled it.
This was QUICK WORK from both! Capitalism in action! Competition creates better products!
(But but before that I had ShakySarge make me one of his hand made ones to use to give credit there)
And now we will see which stands up... the steel one or the aluminum MkII one!
Firstly, no one "had" me make anything. As a bulldog owner I recognized the necessity for a stronger lever and came up with the solution myself. Sadly, I made the mistake of sharing that information in the thread, which will not happen again.
Spent hours upon hours figuring out what to use and then did so. Secondly, if my mind doesn't phase me, I sent most of them out for free save yours that went out in exchange for some cast slugs, which, I am not going to turn down when offered.
Lastly, both aftermarket levers came solely from my hand made levers and to charge 50 a piece is more than absurd especially when using mills instead of doing the work by hand. At the most, I charged 20 bucks shipped. Guess we know who takes advantage of folks and who doesn't don't we?
Anyways, I am already addressing other issues and resolutions with the levers to allow further seating of cast slugs with an oversized port. You can rest assured this information will not be revealed in any thread again.
No one is stopping you from making and selling or giving away your lever this is a free market so please do as you wish. What ever the vendors sell it at no matter who makes it is dependent on cost to build it paying for materials and labor time then adding the normal 30% for profit in most cases. I can’t speak for other vendors but we were asked to make them by many customers so we did to our specs.
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Peek won’t seal but the gen 2 version is much stronger for those wanting to use 4000 plus psi.
Thanks Travis. The saga continues, and this log/project will go to the back burner waiting for the v.2 poppet.
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I had an identical failure on a SS valve early on.... I moved the groove back further from the shoulder.... no more problems after that, even with Delrin.... There simply was not enough shear area between the bottom of the O-ring groove and the shoulder in front of it.... and in addition I think the force from the O-ring, which is mostly on the outer lip of the groove, caused the forward part of the land to bend and tear off.... Making that land wider solved both issues, in any case....
The new "simplified" balanced valve, without the large rear O-ring have a different mode of failure.... The front O-ring is trying to pull the poppet apart, applying a tensile load at the bottom of the O-ring groove.... If there is not enough cross sectional area there for the material being used, the front of the poppet can pull off the main part.... I avoid that on mine by having the steel stem extend right to the front.... Gipetto uses an all metal poppet with a Delrin seat in the valve.... However, one of the guys in the simplified valve thread had several Delrin poppets pull apart at the bottom of the O-ring groove, so it can happen, depending on how it is designed and the materials used....
Bob
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It wasnt originally designed for 4500psi working pressure but the gen 2 is so no more issues.
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Well after all this we will have addressed the air reservoir, lever, and valve for higher pressures. Hopefully that will be enough. ;)
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We sometimes test reservoirs to at least 3X the MSWP.... yet we don't do that for valves.... and I'm as guilty as the next guy.... I do some cursory calculations on the strength of materials, but I have a poor understanding of how plastics are affected by constant load, and whether they are subject to creep, elongation, etc.etc. under constant (or intermittent) stress.... Metals are soooooooooo much easier to understand, IMO....
Bob
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I am actually wondering why Travis doesn't get PEEK to seal, as I see lots of posts where people are making poppets from PEEK. Is it the shape of the Bulldog seat or what?
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I am actually wondering why Travis doesn't get PEEK to seal, as I see lots of posts where people are making poppets from PEEK. Is it the shape of the Bulldog seat or what?
Its because with a balanced valve you eliminate 50% or more of the force holding the valve closed thats why it opens easy so using a very hard material like peek makes getting a poppet to seal very difficult on a production part. sure I could make one and after lapping and truing the valve it will seal thats not something I expect my customers to do and get really frustrated taking the gun apart multiple times trying to get it to seal.
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Makes sense. Thanks for the explanation.
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Makes sense. Thanks for the explanation.
My pleasure David and If you still want one I would make you one you know that right!
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Well, yeah, but I am interested to have a beefed up and stictionless version 2 first, and if it can be strong enough in cheaper Delrin, so be it.
Then maybe if I want to try helium at 4000 psi we try it... lol.
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If the gen 2 works I will reconsider my pressure limit.
Roachcreek
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There is no gen 2 poppet yet, but I do have a temporary one designed for higher pressure with a set back oring groove. I will try to get some quick testing in, although not sure I will have time this week to shoot the 100 yard MOA test that I wanted to, as I will hog hunt with it at the end of this week.
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If I'm thread jacking, please let me know and if needed, delete the post...
Are the Gen1 valves able to be upgraded to Gen2 valves, or are they completely different designs?
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If I'm thread jacking, please let me know and if needed, delete the post...
Are the Gen1 valves able to be upgraded to Gen2 valves, or are they completely different designs?
I understood from discussion with JSAR that version 1 will need a new poppet and thimble to become version 2 in general about their valves. Of course on a JSAR Bulldog valve that is about all they ship anyway since the valve body is the gun block. The part that contains the thimble is also the threaded coupling that the air reservoir tube threads onto, so they might come up with just a replacement poppet on that one, or a poppet and thimble only, without the outer threaded piece, which would be reused. In short, a new poppet for sure, and maybe also a new thimble piece.
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If I'm thread jacking, please let me know and if needed, delete the post...
Are the Gen1 valves able to be upgraded to Gen2 valves, or are they completely different designs?
I understood from discussion with JSAR that version 1 will need a new poppet and thimble to become version 2 in general about their valves. Of course on a JSAR Bulldog valve that is about all they ship anyway since the valve body is the gun block. The part that contains the thimble is also the threaded coupling that the air reservoir tube thread onto, so they might come up with just a replacement poppet on that one, or a poppet and thimble only, without the outter threaded piece, which would be reused. In short, a new poppet for sure, and maybe also a new thimble piece.
Okay cool... I have a Gen1 Bulldog valve I haven't installed yet, and I want to make sure the valve swap is as easy as possible i.e. drop-in...
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I've been following this thread and has encouraged me to do a similar build.
I installed the ss valve last night but I'm unable to fill. I can hear air escaping at the barrel.
I do have the gun cocked.
Any tips?
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Did you install the jsa spring? And if you did don't adjust the hammer spring more than flush with the back of the receiver to start with and cock and fire it a couple of times , hope this helps
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John, the hammer pressing on the valve can keep it open when there is no air in the tube. You can cock it to take the hammer off of it long enough to fill it a little way, and then decock it.
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Yes I am using the supplied jsar valve.
I will try these tips.
Thank you
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I just got mine assembled with the SS valve and ti 4500 tube, no leaks.
Roachcreek
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I just got mine assembled with the SS valve and ti 4500 tube, no leaks.
Roachcreek
Good to hear Lani! I'm looking forward to hearing your results. And I am curious, are you using a depinger in the new ti tube? Length? Other specs on mods you've done? If you don't mind sharing... Thanks Lani
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My first mod was done before I fired a shot through it, that was porting the barrel and valve tp to .277.
Made up a shroud assembly for stealth that is a .277 ported barrel, that has three holes drilled in the barrel just behind the mega Pitbull moderator attached to the shroud.
Next was to make a faster way to change between my two uppers, I drilled the reciever hand guard to access the barrel locating and barrel attachment screws. Now by loosing those two screws three turns, the shroud with short Pitbull moderator and barrel assembly slide off and is replaced with the upper with barrel ported to vent into the shroud and Pitbull mega slides on.
Polished the lead on both barrels.
The
Then I adjusted the trigger to a single stage trigger.
And finally the SS valve and oem lengthy 4500 psi JSAR tube.
I am toying with the idea of making up another upper or reconfiguring what I have to have to a carbine barrelwith short Pitbull moderator and shortened shroud assembly to get maximun velocity, hoprefully 500 FPS with air bolts.
Roachcreek
Roachcreek
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Nice Lani! How about some pictures?
I still want to do some more slug accuracy testing with mine at high power, but I am now too busy for the next month or so to work with my airguns much. I am also patiently waiting for a JSAR v2 valve update.
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I used to post lots of pictures, however now have a IPad Pro and I have not been able to post pictures with it.
I talked with JSAR about v2 of the SS and they have not done anything with it.
I have not had trouble with mine, I have had it for a few months in the oem tube, I did not modify it and kept pressures under 3600 psi. I dry fired it numerous times, but only put 50 or less bullets that I cast that weigh 125 grains through it at that pressure.
I now have my Bulldog filled to 4k to test for leaks but I will most likely run it at 3800 or less, I also have had no issues with the side lever, but keep a new spare in case I do.
Most of my shooting has been with a Lyman 358429, which went cast of 401 comes out at 178 grains and works thrrough the magazine, I shoot that at 2600 psi and it chambers easy, which is why I hypothetically have had no lever problems.
Roachcreek
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I have had 2 version 1 SS Bulldog poppets break from being stored at 4000 psi in a temperature stable environment. Both cracked at one of the oring grooves at right around 1 week of storage. They made me a 3rd one with the groove moved back from the edge a bit, and this one has not broken. I would suggest to lower the pressure to around 3000 before putting it away each time unless you do something similar.
Note to anyone just now reading this thread. Pressures over 3000 psi should never be tried unless you have an aftermarket titanium air reservoir.
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Thanks David, I will do that.
I said I had not modded mine, I did spin it he valve stem in very fine sand paper for just a few seconds because the stem would not enter the raceway when I installed it the first time, if that counts as a mod. It stays in the raceway when I disassemble it and takes some strong fingers to remove ot.
Roachcreek
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Dave is correct, don’t fill the oem tubes past manufactures recommended pressures with any pcp.
The velocity increase you obtain with the SS valve and being able to pressure it to 3000 psi instead of 2600 psi to open the oem valve is worth the price of the SS valve.
If you want to hot rod your Bulldog, buy the ti tube from JSAR.
To rephrase a popular saying in socially acceptable language, “Feces occurs”, and the potential is always there when exceeding recommended pressures.
I personally feel comfortable filling and storing my SS valve/ti 4500 ti tubed Bulldog at 3600 psi, but that is just me based on my limited experience.
On another subject tearing down and assembling the Bulldog, if you over tighten the screws on the plastic stock you can damage the metal threaded Ferrell’s in the stock, replacement ferrets can be obtained from McMaster Carr for the 6-32 screws, #240-006-cr, branded ‘EZLOK’, they are cheap and good to have around.
Also the oring supplied with the oem thimblele for the tube/thimble junction is smaller than the oring that JSAR supplies with the SSvalve,thimble and ti 4500 psi tubeI. I have no idea of the size, but I am going to order spares from JSAR next week.
It is always nice to have extra parts on hand, a lesson I learned from living in the outback for 20 years that still holds true for me after moving to civiilazation.
Roachcreek
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Guys I tried your tips and was successful in filling. Held pressure over night, no leaks.
However, the gun won't stay cocked.
I did install the pitbull trigger so something isnt right.
Will have to tear down down again and see what's going on.
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Tearing the Bulldog down makes it easy for the trigger assembly to flop around and rotate it out of adjustment.
If so you need to adjust the trigger by rotating it. This procedure is also how to adjust the trigger to a single stage trigger, it can be done through the inspection hole covered by that rubber plug in the bottom of the rifle if you have the correct tool to turn the trigger assembly rod, which I do not have.
So without that tool, this is how you do it.
First make sure it is unloaded and the barrel free of projectiles.
Disassemble the rifle again.
You want to screw the rod further into the trigger end, so rotate in that direction , make sure the trigger end of the rod is screwing into the trigger
I think that would be clockwise. Anyway rotate three turns, reassemble it only enough to test the trigger, only screw in the top grip screw and the screw in the trigger guard in front of the trigger, then cock it, hold the cocking lever back while pulling the trigger, if you have a lot of first stage travel, disassemble and turn it again once and the repeat the partial assembly and cock it. If you adjust too far, the rifle will cock but not fire.
You will need to repeat the process, screwing the rod either into the trigger to get rid of the first stage slip, or the other way if you have gone too far and it cocks but will not fire.
A tip, I glue in the pin that holds the trigger to the left side stock half. When assembling the rifle, I hold the safety in place, lower the right side stock half, into place while pinching the safety, then as the two halves go together, you have to move your other hand to pinch the safety through the now two halves of the trigger guard, it makes it easier to stop the safety from flying out of contact.
Hope this helps,
Roachcreek
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Thanks.
It is single stage now, there is absolutely no creep. I wasn't sure if the competition trigger has contributed to this or if the trigger just spun a few times going unnoticed while working on it.
I will tear it down this afternoon and see what I find.
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Thanks.
It is single stage now, there is absolutely no creep. I wasn't sure if the competition trigger has contributed to this or if the trigger just spun a few times going unnoticed while working on it.
I will tear it down this afternoon and see what I find.
I'm very curios to hear how you like the Pitbull polished trigger assembly. I have the tools needed to do it myself. I planned on polishing the pieces but after watching the video and doing a little research, I was considering doing a little grinding too.
And good to hear that she's holding air!
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I suspected you knew most of this, but I did not when I acquired my Bulldog and had to learn myself with the exception of how to do the porting and port size, which Tom Kerrigan instructed me on. I had my wife help me with the porting,she lined up the bit and I drilled out the ports. She can hear me drop a screw on the floor from upstairs, then instantly appears to search for it.
The caution about unloading the guns, is not to talk down to anyone, it comes from a career in LE and watching and hearing the stories about them dry firing their side arms at the tv, clock on the wall, door knobs, cats and dogs and having to replace them. But it is common sense, and like driving a car, the more you do it the greater a chance of a mishap.
Roachcreek
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OP I don't want to thread jack, but this seems like the right place to discuss these mods as you have done it extensively. Please let me know if you feel otherwise.
I adjusted the trigger (rod length) had to make it shorter to get some 1st stage. I now have a very slight 1st stage and a super crisp 2nd stage. Definitely better then the stock trigger.
I was only able to chrony 1 shot string as I was running out of daylight for it the register.
The beginning of my tuning:
95gr Flat Tip Drill Dog Bullets- my practice loads for chrony purposes (I would like to note that some bullets took more force to chamber then others)
~3 turns in from flush
1-932
2-956
3-924
4- Err
5-928
These 5 shots brought psi from 3000 to 2000.
How many turns from flush are you guys running?
My end goal is 930-950 fps using 142gr NSA if possible with stock reservoir and pressures.
I will shoot more stings with continuously more preload and see what happens. Perhaps a titanium reservoir will be added if I can't achieve 280fpe with the 142gr NSA's
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John,
Screw it all the way in.
Air usage is correct.
Roachcreek
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Well got a sunny day here but very windy. So I did a bunch of chrony testings on various bullets. 3k fill
I found that 3/4 turn out from max gave best shot consistency.
95gr DrillDog Flat Tip
-2 turns
1-962
2-956
3-924
4-910
-1 turn
1-977
2-942
3-931
4-905
-3/4 turn
1-977
2-937
3-949
4-907
-1/2 turn
1-968
2-961
3-918
4-885
Max IN
1-943
2-984
3-964
4-929
5-915
NSA 105gr HP
Max IN
1-944
2-935
3-900
4-871
NSA 110gr
-1 turn
1-865
2-884
3-870
4-850
-3/4 turn
1-880
2-876
3-856
4-859
Max IN
1-922
2-902
3-869
4-854
NSA 120gr HP
-3/4 turn
1-822
2-834
3-831
4-810
-1/2 turn
1-814
2-834
3-830
4-821
5-812
NSA 140gr HP
-3/4 turn
1-744
2-759
3-758
4-732
NSA 142gr BHP
-3/4 turn
1-787
2-807
3-807
4-791
5-Err
MAX in
1-805
2-815
3-801
4-779
JSB 81gr
-3/4 turn
1-1035
2-1050
3-1026
4-1001
5-985
I am definetly not reaching the speeds I was hoping for using the 142g bhp. OP, what pressures were you running to acheive the ~930fps mark?
Pitbull now offers a stock size tank that can be filled to higher pressures. This might be happening in the future.
Accuracy tests will follow when conditions permit.
What are your thoughts.
These tests are with the following mods:
-jsar ss valve and spring
-drilled ports to .3 in
-depinger
-emporer v3
-factory 3k fill
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1017 fps @ 4000 psi, spring 4 turns from max for the 142gr from a few short notes on my phone. Note that I run a stock OEM spring with a few coils cut off, and my tunes with this gun a usually for 1 to 2 shots at max power. I would need to look through my notes more closely to tell you more but I am very busy with work for the next weeks so won't be on much.
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I have a theory, based on chrony numbers, that the amount of surface area of the bullet touching the bore has a real effect on bullet velocity.
I ordered from NSA some 152 gr bullets and shot four, 5 shot strings and got an average of 808 FPS.
Shooting the NOE 359-174-FN-CE2 HP at 152gr, same fill and four ea 5 shot strings gave an average of 861 FPS.
I have had a similar difference between a smooth sided cast bullet ment for Hi-tek coating and a grooved bullet of the same weight (both 128gr), the grooved bullet with less barrel friction area was faster. By 43 FPS in this case.
Just pointing this out so people don't make assumptions on what bullets will be right or how they shoot (or group) without testing. Be flexible and open and don't lock into a particular projectile.
FYI - I think why I get such good velocities out of the NSA 142 BTHP is the smaller bore contact.
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All the NSA ammo is .357
No clue what the drilldog ammo is sized at.
I do have the same ammo in .356 but didn't run those thru the chrony.
Yes if you look at the 140gr hp vs 142gr bhp..surface area is playing a role in the numbers for sure.
Is there any reason why jsar advises to not use oem spring or stiffer springs with their ss valve?
Maybe a stiffer spring will help get me closer to goals before I opt for the reservoir.
Side note, my x sight pro came in today, did a quick sight in and all the ammo shot above is grouping very similar at 25 yards.
both 356 and 357 were negligible at 25 yards.
I think for the current tune I will opt for the 110gr in 356 sizing for the hunts.
and I will either need a stronger spring or reservoir upgrade for higher pressures to run the 142gr bhp.
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1017 fps @ 4000 psi, spring 4 turns from max for the 142gr from a few short notes on my phone. Note that I run a stock OEM spring with a few coils cut off, and my tunes with this gun a usually for 1 to 2 shots at max power. I would need to look through my notes more closely to tell you more but I am very busy with work for the next weeks so won't be on much.
No worries, I completely understand, thanks
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Tried to upload some images but failed for some reason
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Carl,
How does that NOE bullet shoot?
Looking a,t the bearing surface I suspected that it would be faster.
They have been out of stock when I check that mold though.
John,
I don’t think JSAR recommends using the oem Benjamin spring.
You are correct that 3/4 turn yeilds a better string. I was going on T Kerrigans initial post on the valve, but they were all single shot strings.
Roachcreek
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The JSAR spring is what you should use with 3000 psi factory air reservoirs. I am using a cut down factory spring because I fill a JSAR titanium reservoir to 4000 psi. In that case a bit more spring is needed than what the JSAR SS valve provided spring can provide.
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Huh, I just checked and all cavity sizes have quantities listed
http://noebulletmolds.com/NV/index.php?cPath=35_578 (http://noebulletmolds.com/NV/index.php?cPath=35_578)
It has been accurate shooting in my Texan, my FLEX and in my Pitbull. TriggerTreat has also shot some and reported/posted good accuracy, plus a few other shooters too.
The newly listed NOE mold should be a bit more accurate though as it is a copy of the 36-168j, another well tested proven bullet
http://noebulletmolds.com/NV/index.php?cPath=35_590 (http://noebulletmolds.com/NV/index.php?cPath=35_590)
NOTE: Accurate to me means the AVERAGE 5 shot group (not just one that was lucky) has to be under 1.5 MOA @ 100 yards. Both these bullets have done 0.75 MOA groups repeatablely
The JSAR spring is what you should use with 3000 psi factory air reservoirs. I am using a cut down factory spring because I fill a JSAR titanium reservoir to 4000 psi. In that case a bit more spring is needed than what the JSAR SS valve provided spring can provide.
I'll confirm on that, I cut 2 coils off the stock spring and used it in my SS valved Pitbull which I usually fill to 3200 and then switched back to the JSAR spring as it gave me amuch better 4 shot shot curve.
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We seem to be talking about two different molds, the one I referred to was not in stock yesterday when I just checked it and it is not even shown today.
It had three thin bands, was listed as a 150 hp Bulldog, the mold number was confusing in that the number, which I don’t remember, would indicate it was in either 160 or 170 grains, but described as a 150 grain. The mold number like I say brought it to my attention because I cast and shoot 36429, which weighs 178 grains but has pretty wide bqnds which should cause much more reassurance than the one I describe.
Update, I found it, it is the 358-163 _hp-pband it is not in stock
Roachcreek
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Ahhhhh, yes I thought you were describing a different bullet.
This one? http://noebulletmolds.com/NV/index.php?cPath=35_299 (http://noebulletmolds.com/NV/index.php?cPath=35_299)
I had the NOE 'Bulldog' bullet mold and passed it on because I wasn't useing/casting with it as:
1. Had a hard time getting the bullets off the pins, even with ALL the tricks and I know them all.
2. It just was not that accurate, 2.5" to 3" at 100 yards, at best.
Looks like it would be great but just did not perform (for me... and the guy I sold it to {with warnings} has not gotten good results either, long range target shooting. But he's shooting hogs in the bottoms at 35 yards or less so it works for his purposes)
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Too bad, it looked very good, never figured out the 163 number on a 150 grain, anyway you just saved me 125 bucks. Don’t you hate spending money on a mold that does not work out.
I am hoping my 358429 shoots better with the 4500 tube, some times blowing the dust off a slug with more velocity behind it helps, if it does, I will have Eric hp it. Right now it expands way flat in duct seal, but that is not a great substitute fior flesh.
Roachcreek
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Too bad, it looked very good, never figured out the 163 number on a 150 grain...
That's 163 as a solid point, 150 as a HP depending on which pin you install in the RG style mold.
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Anyone have any first hand experience with the TalonTunes 5000psi gauge? As to it's quality, durability and accuracy?
Was looking to use this if I went with bully tube.
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John,
Tony usually sells quality gear, I would be interested in one also, so I need to check that out. When my ti tube is filled to 4000, that needle is off the scale and then some.
I see JSAR has one also, I think I might just have them put it in the box when they return my Skyhawk, it is $2.50 more, but I would save that on the shipping.
Roachcreek
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What is everyones thoughts on the pitbull bully tube? Max safe fill pressure with 3:1 safety factor in mind? Its constructed of 2024 aluminum with a .125 wall thickness. States its much stronger then oem tube. Does anyone know what the oem tube is constructed of?
I am aware of both this tube and jsarr titanium tube.
I plan to run 3600-3800 psi max most likely. (higher or lower pressures if needed to obtain 4 shots at ~930 fps with NSA 142g)
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Just to update, I have the bully reservoir on the way. Plan is to cut 2 coils off the OEM spring and begin tuning at 3600psi. I'll follow up with chrony results with the various NSA slugs I have on hand.
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I would not go over 3000 psi with anything except the JSAR titanium tube.
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TalonTunes 5000psi gauge came in today. Looks to be of equal quality to oem gauge. Dial is clear and easy to read in 200psi increments. I really like that the face is black in color. It reads accurate! What else is there to say. Id recommend for sure.
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JSAR has my Bulldog doing some work on it, one of the tasks they are doing is to install their 5000 psi gauge on the rifle. Without a 5k gauge that needle hangs in space with a 4k fill.
Roachcreek
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What hammer spring are they tuning it with for the 4k fill?
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They are not tuning it. I had ported it to .277, but since that time, most are porting them to .30, with my vision, I am confident about porting both my interchangeable uooers myself, but not the valve transfer port, so that is what they are doing along with the gauge while they have it degassed.
My Bulldog has been altered to allow the entire upper, barrel, shroud, endcap to be removed by simply turning the barrel locating screw and barrel retention screw three turns out and sliding the entire unit off.
I did this by drilling two holes through the plastic upper reciever cover to gain access to the barrel screws for this purpose. I did this due to breaking a Pitbull long moderator a couple of years ago disassembling it, so now I JBWeld the Pitbull moderators on the shroud and can switch between the mega and short units in a couple of minutes, both units have lasers to zero the scopes I use on them, Hawke Sidewinder FFp 4x16, Simmons 3x9 turret, Bushnell 14vAR or the UTG reflex sight.
This mod also allows me to put bayonets on both uppers so if overrun and out of ammo, I ca shoot the uppers off as air powered harpoons, I will need to buy a couple of crossbow scopes for this purpose. :D
Now my Diana Skyhawk is a different situation, they are putting a LW Polybarrel, porting to a larger tp and porting the valve, opening up the hammer for a larger spring.
Now about the Bulldog spring, I need to call them tomorrow and ask about that, then order a couple oem springs from Benjamin to alter per their directions.
Short answer on the spring, *(&^ I have no idea until I ask, I suspect it will be the oem minus two coils that the guys here recommend also.
Roachcreek
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Awesome, keep us posted!
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Lani,
I like your mod to be able to remove barrel/shroud. :)
If you are ordering springs from crosman, you may also want to try: #20-R3571-039, It is a detune spring for the bulldog. Maybe it will work without having to cut and grind the oem one?
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Thanks Fuzzy. I called JSAR this morning but Jacob was not in yet, so I will call again this afternoon to get the spring info I need.
Yes that mod of drilling access holes-makes the take down so very easy and in my case changing uppers, especially when in the field or at the range. I need to find some rubber plugs to plug the access holes to make it look more refined.
Roachcreek
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I did something similar, except instead of drilling access holes, I carefully sanded down the edge of the plastic that hooks under the shroud. Now I can unscrew it and get to the barrel retention screws without taking everything apart. The holes are faster, but I didn't want holes showing.
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My new reservoir should arrive by end of week. Also going to test out a heavy spring as well as oem cut and jsar. I think my original goal with the 142 gr averaging 930 fps for 4 consistent shots may not be obtainable with 340cc volume.
The 110 gr is much more accurate in my barrel in 356 sizing. I can dart a crow in the 90 yard range.
New goal is 110 gr averaging 930 fps for as many consistent shots I can get, hopefully a mag worth. Currently shooting the 110 at 850 fps ave. I have shot them as high as 960 fps with no loss in accuracy.
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I just got off the phone with Traviis at JSAR, he said to use the spring provided with the JSAR Bulldog valve.
I advised him many on the forums were advocating the oem spring minus two coils, he said to never mind that, to use the spring JSAR Furnished with the valve.
Seems pretty plain, use the JSAR Bulldog valve spring.
Roachcreek
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From my tests, Jsar spring maxes out in performance at 3200psi. Anything beyond and fps suffers. With the oem minus 2 coils there is 80-100 fps increase and continues to raise with elevated pressures.
I am confused as to why only use the jsar spring. Is this specifically for 3k fills maybe.
Frankly, I am a disappointed in the claims advertised at 3k fills.
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I bought some 120 grain hp bullets from a vendor, his first name was Lee I believe, on AA classifieds, and not having a chronograph at the time, I sent some along with my cast 178 grain 358429 bullets to Tom Kerrigan to test for velocity and accuracy.
He had his Bulldog at the time ported to .277 and was running it without a valve return spring and getting maxim8n velocity at 2600 psi with the hammer spring maxed out.
The 120’s were hitting 915 FPS and grouping 1.5 inches at 60 yards. The 358429’s were at 807 FPS and grouping at 3.5 inches.
Later Tom revisited the test after boring out his ports to .30, he gaiNed less than 10 FPS with the 178 grain 358429 bullet.
These days everyone is going .30 or bigger, with the higher fill rates it would seem prudent to go to .30 with tubes designed for higher pressures.
However with the JSAR valve and at the very least being able to run 3000 psi with the valve if using the oem tube, those velocity increases are significant.
Now Tom raised some concern while testing for valve lock and ran it up to 4000 psi with the oem tube and JSAR supplied spring at maximum load, the velocities went up considerably.
Tom posted those results on the TAG and here.
I don’t see that performance as disappointing.
Roachcreek
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From my tests, Jsar spring maxes out in performance at 3200psi. Anything beyond and fps suffers. With the oem minus 2 coils there is 80-100 fps increase and continues to raise with elevated pressures.
I am confused as to why only use the jsar spring. Is this specifically for 3k fills maybe.
Frankly, I am a disappointed in the claims advertised at 3k fills.
John because most people run 3200psi tunes and if they run the stock spring even with 2 coils cut off it will destroy the valve so we dont recommend using anything but the supplied valve spring NOW that said if using our ti tube it will require more spring but thats up to you and your tuning to determine what that needs to be as it can be a wide range determined by pressure/velocity/and FPE requirements.
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I am with Travis and this is consistent with what I have posted in this thread. JSAR valve should use the JSAR supplied spring unless you are doing tunes with a titanium reservoir and higher pressures than stock.
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Yes this is spot on with my testings and I appreciate the clarification.
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I posted what I was tod and now stand corrected. I will order a couple springs tomorrow from Crosman.
My Bulldog with a .30 porting and 6000 psi Gauge gets back on the 11th.
Roachcreek
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I just got in the extension for the emporer v3 ldc by DonnyFL. The emporer v3 alone reduced the note considerably but with the extension all you hear is the hammer strike. Sure both combined makes for a very long moderator but it whispers now.
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The DonnyFL threaded adapter for the Bulldog is able to move around, even with both screws in it because it doesn't seat very deeply or tightly into the shroud. This will impact your shot accuracy at over 50 yards, if this is important for you. You may want to look into securing that adapter more tightly if so.
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I'll keep a close eye on this. Thanks for your input.
Hey on your tune when you were running 2 full power hunting shots, how much air per shot was it consuming? Closer to 350/shot?
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Just going on memory, yes, in that ballpark. Maybe closer to 300. Start was around 4200 and ending at 3600 or a little less. I never measured that one with the digital gauge, just glanced at the little 5000 psi analog one on the Bulldog.
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Ok thanks.
I won't get to tuning until next Wed so I will follow up with results then.
Thanks to all who have put forth their ideas and experiences.
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I just got my Bulldog back from JSAR, porting the valve from .277 to .30 and installing their 5000 psi gauge.
The gauge has a white dual, numbered to 5k and psi stamped where 6000 would be, but I don’t know if the needle goes that far and have no intention of fining out, I will call it a 5k Gauge for now.
I do love how spell check here exchanges Guatemalan for gauge if you misspell it. ‘Poor spellers of the world untie”, that’s my humor for the day.
My rifle with the oem tube filled to 3600 psi used 2 hundred psi for 5 shots when ported to .277 and with the JSAR spring and using no projectile, I have not tried that test with the 4500 psi tube and .30 porting yet.
Fuzzy,
FYI, I ordered three Benjamin springs yesterday, F from Crosman, the order number for them, taken from their site was the number you furnished for the detuned spring.
Roachcreek
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David,
You have tried both the Pitbull mega and the Emperor without the Add-onis, which is quieter?
I had my doubts about that Donnyfl end cap alighting properly, makes and they even address it on their website.
Being as I have a couple of uppers, I have often thought of a 3rd upper, one with the shroud cut back, the barrel threaded 1/2-20 for the Emperor and the threaded barrel end extending past the end cap which would have the muzzle relieved enough to allow the barrel to pass through. In most of my day dreams about the third upper, the barrel is shortened to 25 inches to gain full velocity with air bolts. Not that I came up with the idea, I see carbines made up on the Bulldog with a threaded barrel stub sticking out.
It seems that would cure a lot of alignment problems.
In my description of how I set up my two uppers, Your posts reminded me that I forgot about relieving the tabs on the front of the plastic upper receiver covers that fit inside the shroud, man how I hated getting those aligned to seat the shroud all the way back. I relieved mine before I got my 2nd upper going.
On my upper with the Pitbull mega, the moderator is JB WELDED in place, but just before the ring on the Megamoderator, I drilled 3 small holes into the barrel to allow air to bleed into shroud better before entering the moderator.
I have not compared the two uppers on the crony to see how much velocity is lost, knowing full well some must be lost, but it seems quieter.
Are any of us with the JSAR T I tube using a depinger? If so which one? Mine that was in the Oem tube, a Pitbull depinger, is now too large to fit in the Ti tube. I have thought of sanding it down and installing a stand-off tube between it and the valve to keep it from migrating to the valve.
Roachcreek
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I don't see any issue with sanding it down a lil bit all while keeping it a tight fit. Hammer it in with a dowl.
I didn't know that tube was a different diameter.
I also use the pitbull depinger. It really works wonders. All that annoying ping in your ear is gone!
I too am curious on hearing how the pitbull v Donny emporer compare in noise output. I primarily went with Donny because I like the look of a cylindrical LDC vs the other design. Plus I preferred metal over a plastic filament.
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On a side note, the OEM spring you ordered is the part number I have listed in my manual.
Are you sure this is the low power spring?
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John,
Yes that Pitbull depinger works wonders, I had one of his first bunch he put out and the sound difference, with the mega was impressive.
I think that part # is the full power spring not the detune spring. I could not find a detune spring on their schematics, did you?
Last night I filled my ti tube to 4200, then shot 5 times with no projectile. The air usage was only 300 psi total for all 5 shots total. I know from experience that at 3500-3600 psi with the JSAR spring turned all the way in, I would have used 200 psi per shot, either with or without projectile.
Matt always said he would replace those moderators is they wore out, I find them fragile to remove, but I am ham fisted due to poor eye sight, that is why I glue them in and remove the shroud, barrel et.al., when I disassemble the rifle.
Roachcreek
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I have never seen anything about a detuned bulldog spring from Crossman.
I see that Crossman offers one for the marauder though.
Do you have a chronograph? Looking forward to your shot strings at x psi and spring combination.
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It is going to be a couple months until my son gets his house built. He bought 2 lots total of 18 to 20 acres that are on the outskirts of Town and but up against BLM land. I may get out to run them over the box at the local shooting spot, it is very rural here, just need to take a cab as the wife and I do not drive.
Roachcreek
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Sorry, missed the posts on asking about the detune spring.
Did you try ordering it with a "20" in front of it? See my order below. Both springs are on the order.
It has the same length and OD, but the wire size is 0.010" less in diameter. I think I got the number from someone at crosman CS. It is not the airbow springs.
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No I ordered it over the phone.
I have the new valve, version 2, but no oem spring. JSAR is sending out a new spring for it, hope to get out and get some numbers this weekend.
Roachcreek
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As far as I know, the phone is the only option. Back when I ordered these, May 2017, it was hit or miss if they sent out order details via email. This order was one of the lucky ones, otherwise I had only documented it in: https://www.gatewaytoairguns.org/GTA/index.php?topic=126825.msg1242622#msg1242622 (https://www.gatewaytoairguns.org/GTA/index.php?topic=126825.msg1242622#msg1242622)
Outside of this spring part number, I have not seen crosman use a preceding number like that. Easy to assume it was the item number id from the schematic, which is actually #22, for the hammer spring.
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Small update.
New shot strings with custom spring and 3200psi fill
Max velocities:
NSA 142- 910fps
NSA 110- 990 fps
Nosler 145- 915 fps
I found tightest shot string with -1.5 turns
NSA 110
970
945
922
900
Each shot uses about 180psi. 5 shots brings 3200 to 2300
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OP,
Have you tried those 150gr Anvil HP from HiKal bigbore yet?
I just ordered some in 358 sizing.
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OP,
Have you tried those 150gr Anvil HP from HiKal bigbore yet?
I just ordered some in 358 sizing.
Never heard of them before you mentioned them.
Apparently Hi-Kal is using a few of the fine NOE molds from looking over the product page.
I have most of the molds for the bullets they are selling and the one they are calling the Anvil was not the top in accuracy in my testing at longer ranges like 100 yards, adequate but not the best. I had a hard time getting them off the pins as the HP is so deep, and trouble with fill out voids at the base of the HP cavity. [A bubble forms at the point of the pin as lead fills the mold... it's a common problem but has solutions]
http://noebulletmolds.com/NV/index.php?cPath=35_299 (http://noebulletmolds.com/NV/index.php?cPath=35_299)
The Bandit is the Bob's BoatTail, NOE 357-136-FN-BZ4 in HP and shoots well in my FLEX and Pitbull (used to be a Bulldog) http://noebulletmolds.com/NV/index.php?cPath=35_527 (http://noebulletmolds.com/NV/index.php?cPath=35_527)
The Renegade is the BBT I asked Bob to modify the nose diameter and it is very accurate in my and a couple other guys .357s, NOE 359-174-FN-CE2 in HP
http://noebulletmolds.com/NV/index.php?cPath=35_578 (http://noebulletmolds.com/NV/index.php?cPath=35_578)
Haha, maybe they will test the new .357 airgun bullet and stock it.... http://noebulletmolds.com/NV/index.php?cPath=35_590 (http://noebulletmolds.com/NV/index.php?cPath=35_590)
Like I said, have some other molds for bullets they are stocking and although generally I do not shoot lighter slugs (most stock guns can only shoot the lighter slugs well due to lower power) still bought the molds snd some did good in testing, sure would have been cheaper to buy a hundred from a company to test rather than what I had to do, buy the mold, haha.
Anyway, hope they do well, if I was not a DIY caster I'd try their output. We need more good companies serving our hobby! And allowing us to test a variety of bullets to weed out what works and what does not in the different rifles.
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OP,
Have you tried those 150gr Anvil HP from HiKal bigbore yet?
I just ordered some in 358 sizing.
Richard krebbs at Hikalbigbore makes great bullets for the bulldog. I use the Anvils in mine and they are excellent. His quality control is amazing compared to other places that I have ordered from. His Stingers also perform great with the bulldog. I have a few boxes that I keep on hand as well.
You will love the Anvils. In his gallery, the Anvils that were shot from the bulldog by Matt in TN was a group I shot for him during testing and I shake A LOT. Most folks stack them on the targets.
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OP,
Have you tried those 150gr Anvil HP from HiKal bigbore yet?
I just ordered some in 358 sizing.
Richard krebbs at Hikalbigbore makes great bullets for the bulldog. I use the Anvils in mine and they are excellent. His quality control is amazing compared to other places that I have ordered from. His Stingers also perform great with the bulldog. I have a few boxes that I keep on hand as well.
You will love the Anvils. In his gallery, the Anvils that were shot from the bulldog by Matt in TN was a group I shot for him during testing and I shake A LOT. Most folks stack them on the targets.
Did you have a chrony available during the accuracy testing? Curious how fast these can go before negatively effecting accuracy.
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I agree! We need more quality vendors producing various slug designs and weights.
I was looking for something heavier then the 142 NSA that would fit in the magazine and I came across these.
Glad to hear positive feedback.
Maybe someone can touch on this..through my chrony testings, shot strings are tighter with heavier slugs such as 142 NSA vs lighter slugs as in the 110 NSA I currently use.
Are these typical results?
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OP,
Have you tried those 150gr Anvil HP from HiKal bigbore yet?
I just ordered some in 358 sizing.
Richard krebbs at Hikalbigbore makes great bullets for the bulldog. I use the Anvils in mine and they are excellent. His quality control is amazing compared to other places that I have ordered from. His Stingers also perform great with the bulldog. I have a few boxes that I keep on hand as well.
You will love the Anvils. In his gallery, the Anvils that were shot from the bulldog by Matt in TN was a group I shot for him during testing and I shake A LOT. Most folks stack them on the targets.
Did you have a chrony available during the accuracy testing? Curious how fast these can go before negatively effecting accuracy.
I have a high with the Anvils of 944 FPS in a modified bulldog. They were just as accurate at 750 as 944.
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The strings are more consistent with heavier slugs from my experience as well. The smaller.357, .356 and .355 were not nearly as accurate and did not yield the same consistency within the strings.
That being said, I still use the factory valve(modded) and factory air tube so this could change if I went aftermarket.
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Once these arrive, I will do some fine tuning and will report back with my chrony strings.
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Anvil 150gr in 358 sizing may be too big for my barrel as its takes much more force to chamber and the lower velocities I am getting.
Still tuning for best mix in power and consistency.
Best string so far
846
848
873
NSA 142gr
973
951
863
If that 3rd shot was closer Id be a happy camper.
Need to order more ammo and continue testing.
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I'm going to bump this thread.
I've been having issues with the jsar ss valve so I have swapped back to OEM valve.
Ports ported to .3
Custom hammer spring
Hammer polished
Emporer LDC
2900 psi fill
NSA 142
859
861
846
About 225psi/shot
This is my best 3 shot hunting string I could acheive so far.
Shooting off a bipod is about 1.25 inches at 70 yards.
Back when I was shooting around 960 fps, accuracy was reduced. I don't think it's the projectile but probably the bulldog itself. I think there is alot of flex happening when you near the 300fpe mark.
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I'm going to bump this thread.
I've been having issues with the jsar ss valve so I have swapped back to OEM valve.
Ports ported to .3
Custom hammer spring
Hammer polished
Emporer LDC
2900 psi fill
NSA 142
859
861
846
About 225psi/shot
This is my best 3 shot hunting string I could acheive so far.
Shooting off a bipod is about 1.25 inches at 70 yards.
Back when I was shooting around 960 fps, accuracy was reduced. I don't think it's the projectile but probably the bulldog itself. I think there is alot of flex happening when you near the 300fpe mark.
Have you installed barrel supports in the shroud? Mine gained a lot of accuracy with them.
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I have them but not installed.
I'm not sure if there were printing errors when pitbull made them but they are way to small diameter to fit.
I have not gotten abound to dremmeling them out to fit yet.
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Several of them that I had received were so loose, that they would slide down from their own weight and so not really usable without securing them in place along the barrel. They do not have good print consistency.
I have also had issues with their moderator prints, but to their credit, they sent me replacements.
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I'm trying to get another 40 fps more with these 142 NSA. Anything higher then 2900psi shows signs of valve lock. Adding shims to hammer spring yeilds no increase in fps.
Is this the max?
The 110 NSA shoot around 990fps with current tune for the 142 NSA.
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I agree with the print consistency. I had to sand out two to fit as well. To secure them in place I used some steel wool at the points I wanted them and then used quick curing epoxy to keep them in place. Just be sure that they are all exactly lined up before using the epoxy or it won’t fit in the shroud.
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I'm trying to get another 40 fps more with these 142 NSA. Anything higher then 2900psi shows signs of valve lock. Adding shims to hammer spring yeilds no increase in fps.
Is this the max?
The 110 NSA shoot around 990fps with current tune for the 142 NSA.
That sounds about right until someone figures out how to get even more.
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I tested the HiKal BigBore 150gr Anvils a while back in 358 but they were much too tight. Just got them in 356 sizing and performed extremely well.
Anvil 150gr
2900psi fill
840
847
842
About 1/2 inch at 70 yards. Most accurate slug I have tested yet. These also leave a much bigger exit in 3/4 plywood vs the 142 NSA.
These cost more then NSA at $.44/slug not incl. shipping.
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I tested the HiKal BigBore 150gr Anvils a while back in 358 but they were much too tight. Just got them in 356 sizing and performed extremely well.
Anvil 150gr
2900psi fill
840
847
842
About 1/2 inch at 70 yards. Most accurate slug I have tested yet. These also leave a much bigger exit in 3/4 plywood vs the 142 NSA.
These cost more then NSA at $.44/slug not incl. shipping.
The Anvils are excellent out of the bulldog. A bit more expensive but certainly worth the money for a hunting round.
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I am slowly getting the interest to come back and hack about on my Bulldog a bit more.
As there has been no further third party accessory developments to address the design issue of the barrel and overall rifle stiffness, I am brainstorming ways to address this. It could certainly use it, especially in the higher FPE tunes, like the 350 FPE tune I was hunting with this past spring.
Earlier I had one idea, which was to epoxy in the barrel supports, making the barrel and shroud one. Travis suggested to hold off as they might come up with some offering, but they never did (although I am sure they would have done something custom if I wanted to pay). This would give a huge increase to barrel rigidity, and also go a long way to reduce flex within the entire package. The barrel (with shroud permanently attached), would still be removable. This is possible by grinding down the plastic at the end of the breech clamshell that normally goes under the edge of the shroud, so that it can be removed to gain access to the barrel screws.
Another idea, rather than the above, would be to sleeve the barrel with carbon fiber of two sizes concentrically, with the outer one being longer and of the same ID as the larger breech end of the barrel, and then countersink into the breech. Two are needed due to the tapered barrel.
Then, I can think of progressively more extreme, and expensive, measures to stiffen it all, such as changing the stock, barrel, and etc.
I am currently leaning heavily on the first idea, because it is the cheapest, and I don't really want to invest too much more on the platform than I already have. I also like the current form factor, and like it for the utility it has, even if I am rough with it out in the field.
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I used epoxy for my barrel mounts and bought three sets and installed them. It isn’t going anywhere. However, I would definitely rather use 4- 3.5-4.5” printed mounts so that more actual surface area was covered and made solid contact with the shroud.
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I used epoxy for my barrel mounts and bought three sets and installed them. It isn’t going anywhere. However, I would definitely rather use 4- 3.5-4.5” printed mounts so that more actual surface area was covered and made solid contact with the shroud.
Great! You tried the earlier idea already. Are the barrel supports also epoxied to the inside of the shroud? Can you characterize the impact this had to your groups versus the barrel supports alone?
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I did not have to epoxy them to the shroud due to the tight space. I did add epoxy to the three sides where needed and sanded them down to fit.
My groups shrank considerably with an average reduction of .45” at 50 yards. There were some slugs that already shot that tight and they literally started stacking as one ragged hole. I will be ordering another bolt and linkage assembly after the first of the month to try a couple other “modifications”.
The key to epoxy when mounting the braces is to do them one at a time with the rear shroud mount on and use the shroud to align each one. It’s slow and methodical but worth it in my opinion.
By the way. I found the two boxes of slugs in my wife’s car still on the usps boxes.
They will ship after the first as well. Let’s just say, when I found them I was a bit unhappy!!!
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when matt and paul pitbulled my carbine bulldog, they reinforced my barrel, shroud and added several supports. then installed there version of an LDC adapter that is
much stronger mounted than the other folks have to offer.
along with other mods & cocker spaniel, its a much different machine now.
i dont have the high pressure tube but my pitbull is extremely accurate out to 50yrds with 3 shots starting @ 250FPE.
soon as the new HP tubes come in, i'm going in head first !!!
i'm wanting 325+FPE..... 8)
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when matt and paul pitbulled my carbine bulldog, they reinforced my barrel, shroud and added several supports. then installed there version of an LDC adapter that is
much stronger mounted than the other folks have to offer.
along with other mods & cocker spaniel, its a much different machine now.
i dont have the high pressure tube but my pitbull is extremely accurate out to 50yrds with 3 shots starting @ 250FPE.
soon as the new HP tubes come in, i'm going in head first !!!
i'm wanting 325+FPE..... 8)
The supports I used were from pitbull. Good stuff if secured properly. No comment on the cocking arm.
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No comment on the cocking arm.
i remember you telling me about that...... ;)
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No comment on the cocking arm.
i remember you telling me about that...... ;)
Lmbo. It happens
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when matt and paul pitbulled my carbine bulldog, they reinforced my barrel, shroud and added several supports. then installed there version of an LDC adapter that is
much stronger mounted than the other folks have to offer.
along with other mods & cocker spaniel, its a much different machine now.
i dont have the high pressure tube but my pitbull is extremely accurate out to 50yrds with 3 shots starting @ 250FPE.
Hi John. I have had both their barrel supports and LDC that supports the barrel since early in my thread here. My Bulldog does shoot accurate, and on par with most others I have seen posts on. This is a 1 inch group at 75 yards (5 or 6 shots). I want to have that same sized group at 100 yards (MOA), and at 350 FPE. For that, something more will be required, like my epoxy idea.
Matt, what kind of improvement did you see with the epoxy, vs without? Did you mean that adding epoxy gained you .45" more accuracy versus jo epoxy but still us9ng the supports, or do you mean no supports vs supports that were epoxies.
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soon as the new HP tubes come in, i'm going in head first !!!
i'm wanting 325+FPE..... 8)
I really hope you are speaking about a titanium tube, and not an an aluminum one. We have been over that topic. Please see earlier in the thread.
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yes titanium... not my first rodeo....... ;)
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yes titanium... not my first rodeo....... ;)
Good deal. :D
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when matt and paul pitbulled my carbine bulldog, they reinforced my barrel, shroud and added several supports. then installed there version of an LDC adapter that is
much stronger mounted than the other folks have to offer.
along with other mods & cocker spaniel, its a much different machine now.
i dont have the high pressure tube but my pitbull is extremely accurate out to 50yrds with 3 shots starting @ 250FPE.
Hi John. I have had both their barrel supports and LDC that supports the barrel since early in my thread here. My Bulldog does shoot accurate, and on par with most others I have seen posts on. This is a 1 inch group at 75 yards (5 or 6 shots). I want to have that same sized group at 100 yards (MOA), and at 350 FPE. For that, something more will be required, like my epoxy idea.
Matt, what kind of improvement did you see with the epoxy, vs without? Did you mean that adding epoxy gained you .45" more accuracy versus jo epoxy but still us9ng the supports, or do you mean no supports vs supports that were epoxies.
An improvement in accuracy and smaller shot groups compared to just the supports alone.
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Has anybody figured out a way to break 250 fpe on oem valve yet? no ss valve.
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Has anybody figured out a way to break 250 fpe on oem valve yet? no ss valve.
i dont think that matt and paul installed another valve other than stock, but maybe did resize the ports on my pitbull carbine.
"@3800psi i should be getting over 300fpe"....hopefully when the new airtube
comes in.....
as it stands now, 250 fpe with 3000+psi ;)
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I'd like to know how they got past valve lock on stock valve. With a heavy spring and .3 ports, valve lock is still present and max fps is at 2900 psi.
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My factory valve bored to .28 has gotten up to 296 FPE without any lock.
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My Pitbull, which my TP measuring around .3 (I think I remember him telling me he used an N drill?), using a stock valve and spring (spring backed1/2 turn off of coil bind) and filled to 3200 shows no valve lock.
Using the 152gr BBT ( http://noebulletmolds.com/NV/product_info.php?cPath=35_578&products_id=5489 (http://noebulletmolds.com/NV/product_info.php?cPath=35_578&products_id=5489) ) I'm getting a hunting tune string of 867, 868, 847, 827, 806 and really, the first two shots are all you should need.
The FPE of the first shot is 252.
Filled to 3400 I've got valve lock
Note these pressures are not based on the rifle gauge but are from a calibrated 2" on my fill adapter
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My factory valve bored to .28 has gotten up to 296 FPE without any lock.
This has me thinking something is wrong with my rifle.
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Anvil 150gr
2900psi fill
840- (235 fpe)
847- (239 fpe)
842- (234 fpe)
Any higher fill psi exaggerates the bell curve with no increase in peak fps.
Can you please elaborate on specifics on your 298 fpe.
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I just bought a NOE 358-152 mold and have it cleaned and ready to do the heat treatment and smoking.
What HP pin works for you casters and shooters of this bullet in your Bulldog.
Roachcreek
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Okay, I have the RG brass mold, installed a couple different pins, went with the funk HP pin.
Roachcreek
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Anvil 150gr
2900psi fill
840- (235 fpe)
847- (239 fpe)
842- (234 fpe)
Any higher fill psi exaggerates the bell curve with no increase in peak fps.
Can you please elaborate on specifics on your 298 fpe.
As stated. Factory valve, ported to .28 and polished. Same with barrel port. No valve spring, transfer port removed, Steel lever, spring full in and out 1/4 turn. 3k fill off of a fill gauge, not the one on the gun. Max speed obtained so far is 944 with 150gr Anvil sized to .357 for 296.8FPE
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Okay, I have the RG brass mold, installed a couple different pins, went with the funk HP pin.
Roachcreek
I found that to be the most accurate in my Pitbull and FLEX and casts 148gr in 1:40 alloy.
I did have to polish the pins a bit more with crocus cloth (chucked the pin in a drill and used the crocus) then smoke them to get good drop off. Took a 825 temp and I'm getting perfect fillout.
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Thanks for the info. I will chuck them up and go after them with 1500-2000 grit.
Roachcreek
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Anvil 150gr
2900psi fill
840- (235 fpe)
847- (239 fpe)
842- (234 fpe)
Any higher fill psi exaggerates the bell curve with no increase in peak fps.
Can you please elaborate on specifics on your 298 fpe.
As stated. Factory valve, ported to .28 and polished. Same with barrel port. No valve spring, transfer port removed, Steel lever, spring full in and out 1/4 turn. 3k fill off of a fill gauge, not the one on the gun. Max speed obtained so far is 944 with 150gr Anvil sized to .357 for 296.8FPE
Only difference is I'm going off the talon tunes gauge mounted on rifle that replaced OEM. It has 200 psi increments.
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I picked up a 2 1/4 gauge to have a more precise fill. I have found that the Talon tunes gauge on gun reads 100 psi higher then the bigger dial gauge. I must say I am impressed with Talon Tunes 5000 psi gauge.
In reference to previous tune with NSA 142 at 2900 psi, it is in fact a 2800 psi fill. I'm not sure why I don't get better performance at higher fills as some members are indication with their ported stock valves with all modifications being very similar.
I moved on to tune the NSA 110gr at 2900 psi
947
947
940
I am very happy with these results.
I also did some comparisons of penetration and exit channels with different rounds against 3/4 inch plywood.
I tested NSA 110, NSA 142, Anvil 150, Grizzly and polymags at 30 yards.
Polymags and NSA 110 made the most damaging exit wound. Smallest to biggest exit was NSA 142(855fps), Grizzly (1080fps), Anvil 150 (842fps), Polymag (1050fps), NSA 110 (944fps).
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I bought the JSAR 5000 psi gauge, seems to follow my Joe B fill gauge very closely.
I cast with the Hp pin in the NOE 358-152, first run the bullets fell out with no trouble. Next casting section they stuck.
Not wanting to beat on my mold even with a rawhide mallet, I put in the dimple pin, makes a HP, just not as deep and casts at 163 grains, have not shot any yet, but that mold really casts and ejects better with the dimple pin, and really those dimple bullets will kill any cardboard box I need to kill.
Roachcreek
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I reread my above post. I do not hit my mold, iI hit the hinge pin with a raw hide mallet, but the force required to eject that bullet will still shake it loose.
I need to try the 2 cycle oil on the tip of the hp pin fix, but first I need to see how the dimples fly.
Rogachcreek
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I got 865 FPS today with the NOE152 grain bullet.
SPECS;
.30 porting, oem valve, heavier spring 4 turns in -spring was supplied for JSAR valve, 2900 psi fill, 2nd shot from 6 feet, first shot was an err, starting pressure 2900 psi ending after 2 shots 2600 psi, first shot sounded slightly weaker than 2nd shot which was hellashish, NOE 152 hp” 40-1 sized .358, valve spring in, but will take out on next tear down.
Barrel is cut to 27 inches.
Roachcreek
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Lani, if you hunt with the NOE 152, please post how the bullet does because I would like feedback from others confirming that I got the HP cavity juuuusssttt right and if there is enough retained bullet weight to carry through for a good exit wound.
At 865 FPS, that's 243 FPE so should be good for deer, hogs and large varmints.
I have mine* all sighted in at 85 yard zero which at 865 FPS would be: 0" at 12 yards, 3.4" high at 50 yards and -3.4" low at 100 so that easily covers most of my hunting ranges for 'Point Blank Range' quick kill zone shots (without having to do a lot of range and trajectory mental calculations).
* .357 Texan, Pitbull, SuperFLEX and my "secondhand" Slayer {still have not received the new Slayer from AAA though}
(the Slayer gets 977 FPS avg [fill 3500] with the NOE 152 which casting @ 800 degrees using 1:40 alloy drops 147gr)
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...I'm thinking about running a low power bulldog with a regulator, for high shot counts, at about 80 FPE... and I was wondering how the JSA valve SOUNDS.
I mean, with a heavy moderator, the loudest sound is right now the hammer ping -- so, with a far lighter hammer, does it ping much less?
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...I'm thinking about running a low power bulldog with a regulator, for high shot counts, at about 80 FPE... and I was wondering how the JSA valve SOUNDS.
I mean, with a heavy moderator, the loudest sound is right now the hammer ping -- so, with a far lighter hammer, does it ping much less?
The JSAR valve is balanced, so it needs much less hammer strength to open, and will therefore be quieter. On a Bulldog the muzzle blast is the loudest event anyway, so unless you have truly tamed that bark already, I don't think it will make that much difference. The ping sound that the Bulldogs make is often the reservoir resonating. Have you put a depinger in it? Pitbull sells one.
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I have a JSAR valve and the TP opened up and the pitbull depinger with their mega moderator. No reg then put a .25 Mrod hammer spring in (6,8,10lb not sure) and milked 10 shots at 95-105 fpe spread @ 30 yards it was acceptable, still had a little bark. Pellet hitting the spinners was louder, but pellet on metal isn't that quiet.
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...I'm thinking about running a low power bulldog with a regulator, for high shot counts, at about 80 FPE... and I was wondering how the JSA valve SOUNDS.
I mean, with a heavy moderator, the loudest sound is right now the hammer ping -- so, with a far lighter hammer, does it ping much less?
80FPE seems very slow for the available pellets, but here is my thread of a 130FPE Bulldog, using a reg and longer air tube: https://www.gatewaytoairguns.org/GTA/index.php?topic=126825.msg1242622#msg1242622 (https://www.gatewaytoairguns.org/GTA/index.php?topic=126825.msg1242622#msg1242622)
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But have you had stuck pellets at >2000 psi?
I plan on going regulated ~2000 / ~135 BAR with an extended reservoir that is rated for at least 250 bar fill pressure.
The JSAR valve is balanced, so it needs much less hammer strength to open, and will therefore be quieter. On a Bulldog the muzzle blast is the loudest event anyway, so unless you have truly tamed that bark already, I don't think it will make that much difference. The ping sound that the Bulldogs make is often the reservoir resonating. Have you put a depinger in it? Pitbull sells one.
Got an emperor and regulator, and the hammer is the loudest part right now, before the impact.
You'd think DIRT would be more quiet, but most hits sound like whip cracks regardless.
The dream is being able to fire 30 grizzlies or balls from an extended reservoir at 20 yards into and out of my garage with my secondary bulldog.
Just the cheapest possible bulk ammo -- saving the more expensive ammo for the long range max power build and 100 yard target practice.
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I dusted off the Bulldog and ran some maximum numbers at 4300 psi (titanium air reservoir) just for fun.
178gr 958fps 363fpe
142gr 1042fps 342fpe
I am thinking about selling it because I am now spending so much time with the Texan, and want to focus on new projects. On the other hand, it's nice to have. Somehow I need to thin the heard. :D
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Anybody working on a 7mm conversion with the bulldog?
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David,
I have been thinking the same thing. My ti tube with valve is sitting in the floor in my Air room on the floor.
What I need is a stock 2nd Bulldog ro put it on.
Rochcreek
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A 7mm Bulldog?
See this thread and post #19
https://www.gatewaytoairguns.org/GTA/index.php?topic=165806.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=165806.0)
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Wow David that's screaming for a Bulldog!
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Wow David that's screaming for a Bulldog!
Yeah, that's a real declining tune, but fun to max it out. If I tune it for 2 shots equally and a only 4000 psi fill, it will get 325 FPE each shot. With a 3 equal shot tune, it gets 300 FPE. I usually hunt with it using the 2 shot tune in case I were to need a follow up shot (and of course it can shoot more than 2 shots, they will just be a bit less powerful). 4000 is a reasonable maximum to allow for fills out while hunting from a larger 45000psi bottle, especially because once the tank is outside, it gets cold and can easily drop a few hundred psi.
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A 7mm Bulldog?
See this thread and post #19
https://www.gatewaytoairguns.org/GTA/index.php?topic=165806.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=165806.0)
I will be following your thread pertaining to this conversion! Thanks