GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Firewalker on February 09, 2021, 02:55:30 PM
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I have an issue with my DAR that I am hoping this post will be a place to collaborate and discuss a fix that is permanent and affordable.
Here we go: The shroud is moving my barrel and throwing pellets into the shroud cap!
Please see the targets attached below, #5 shows an "on target" shot that I was able to repeat in the next three shots with the barrel shroud removed but with the shroud attached, the pellets all fly up (#1 & #2 went 7" & 6" above and to the left) and even loosely threaded on and the front O-ring removed, the pellet hits above and to the right as much as an inch with #7 showing a 2.5" rise when tightened but with the endcap removed and the interior nut loose.
Target #9 once again with the shroud removed is right on the bull.
Looking at the second picture, you can clearly see lead on the edge of the cap where pellets have been striking.
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Haven't touched a gen 2 but assume they are still using the same barrel to shroud support and cone-shaped baffles as the gen1. I never had an issue with clipping, but did notice how fragile the aluminum air cylinder to shroud barrel band was, and how easy it was to strip the set screws if not careful. I would check that when attaching the barrel band you are not accidentally getting the shroud skewed in relation to the centerline of the action and air tube. If skewed it will throw your shots left or right and can affect vertical poi.
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The grub screws and threaded holes on the barrel band are good to go, the shroud is left to float and the grub screws are set evenly from side to side so as to not skew the band.
The baffles are tubes with a "washer" end seen below.
Trust me, this is not an issue on my end, everything is tight and properly torqued, I have millions of PB rounds sent down range in my lifetime including 1000yd open sight competitions in the late 80's with Garands.
I took correspondence courses for gunsmithing in the early 90's and have certificates in many mechanical disciplines so lets focus instead on the gun and how to correct the setup at the factory that is allowing for the misalignment that is causing clipping. I dont mean to sound like a jerk, I'm just frustrated and dont want to waste time with basics unless there is good reason to do so.
Actions taken so far:
-Removed the shroud and barrel band from the DAR awaiting return, swapped them out after checking runout (the original was MUCH better with only 0.002" of runout while the replacement is at 0,007" of runout at the center!!). I also swapped out the baffles, alignment block and cap. POI and POA are better but still off about .097" overall at 10m.
I hesitate to remove the barrel due to the fourth grub screw being at the bottom of the barrel band above the reservoir which would have to be removed and replaced, voiding may warranty. Removing the shroud does not affect the warranty according to Joe at DAR.
Do I jack the barrel up after loosening the three grubs holding the barrel to the breach and see if that helps or will this deform the mild steel the barrel made from?
Haven't touched a gen 2 but assume they are still using the same barrel to shroud support and cone-shaped baffles as the gen1. I never had an issue with clipping, but did notice how fragile the aluminum air cylinder to shroud barrel band was, and how easy it was to strip the set screws if not careful. I would check that when attaching the barrel band you are not accidentally getting the shroud skewed in relation to the centerline of the action and air tube. If skewed it will throw your shots left or right and can affect vertical poi.
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What does your crown look like?
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Fantastic! The unsupported barrel shoots great, see targets 5 & 6 below.
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I checked the barrel alignment with the three top screws in place, it's almost 0.018" out, drooping in the front, I am going to loosen the three screws and "jack" up the barrel to match the height at the receiver.
(later)
I got the barrel raised to be even at a gap of 0.0212" across the whole length. Wish me luck!
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The shroud support that slides on the end of the barrel. How loose is it on the barrel? And how loose is it in the shroud? I suspect bother are a little on the loose side causing your problems.
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What happen if you remove all the baffles and the spacer that goes over the narrow part of the barrel and put the end cap back on? Are the pellets clipping the end cap? It seems something inside the shroud is pushing the barrel off center.
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Is the muzzle on a DAR barrel threaded?
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It looks like the rear shroud mount slides over the barrel and is secured with grubs. How sloppy is the fit on the barrel. Remember, a little off on the back of the shroud is a lot off by the time you get to the front.
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What happen if you remove all the baffles and the spacer that goes over the narrow part of the barrel and put the end cap back on? Are the pellets clipping the end cap? It seems something inside the shroud is pushing the barrel off center.
He would blow his end cap to smithereens .
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Is the muzzle on a DAR barrel threaded?
It is not.
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On the DAR, there is an o ring holding the barrel to the clamp and two grubs holding the clamp to the reservoir, its tight and there is zero movement.
The shroud support that slides on the end of the barrel. How loose is it on the barrel? And how loose is it in the shroud? I suspect bother are a little on the loose side causing your problems.
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With the barrel sag, I was very hesitant to do that since I knew it would clip the cap really badly! The barrel was sagging 3/64" front to back.
What happen if you remove all the baffles and the spacer that goes over the narrow part of the barrel and put the end cap back on? Are the pellets clipping the end cap? It seems something inside the shroud is pushing the barrel off center.
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No, sorry, its just turned down.
Is the muzzle on a DAR barrel threaded?
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So the piece they use to center the business end of the shroud is a slip fit I’m guessing. I would be looking at correcting the issue from the breech end of the shroud. It just depends on how tight their tolerances are.
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Its very tight, there is an o ring in the clamp and 2 grubs in the clamp for the reservoir.
It looks like the rear shroud mount slides over the barrel and is secured with grubs. How sloppy is the fit on the barrel. Remember, a little off on the back of the shroud is a lot off by the time you get to the front.
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If the rear shroud mount is a nice tight fit you are going to have to chuck the barrel up and check the runout on this.
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I "jacked" the barrel up and got shim to fit 0.0212" across the barrel length. I also tightened the inner nut over the baffles and then turned the shroud by hand on very tight. I am hoping to add some stabilization to the barrel assembly this way.
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If this is a Chinese gun, you might want to have a few drinks before you start to spin the barrel. I have seen plenty that the bore wasn’t even centered in the barrel.
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No-can-do, I need to maintain my warranty. So far, I am in the "safe zone" with DAR as removing the shroud and cleaning the baffles is maintenance but removing the reservoir is not. :-\
If the rear shroud mount is a nice tight fit you are going to have to chuck the barrel up and check the runout on this.
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;D No Doubt! I am already thinking about getting a replacement barrel but want to wring all I can out of this one first.
OK, back from the shop, this target looks much better but still not hitting the bull all the time. I am confident that I am pulling on the bull center as I am recording the shots with a through scope device. Watching the playback shows clean breaks and the same muzzle jump on each shot. The shots are too close to see the pellet flight since they are still climbing to the bull from only 10m.
If this is a Chinese gun, you might want to have a few drinks before you start to spin the barrel. I have seen plenty that the bore wasn’t even centered in the barrel.
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Here is a question for the brain trust here: How often do I clean the barrel? With PB's I clean it after every session. With airguns, I only patch and never scrub and haven't done a polish with Flitz as I normally do.
This barrel has about 500 pellets through it so far, I would think I would have a good seasoning by now...
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I.ve had a clipping issue for a few weeks...it hits end cap at 5 o'clock (see pic below) what concerned me was shroud alignment and to tight a tolerance (.25" opening in end cap IMO). My Avenger, also a .22 has a .375 opening in the end cap with no issues.. I have not removed or disturbed shroud as I also have a leak that lowers fill pressure 800 psi in 4 hours...I'm getting ready to start the warranty process...
I have read on other forums that some have drilled out end cap and cured their issue....I do not want to do that because of the leak.
https://u.cubeupload.com/crazyhorse4/IMG0574.jpg
I like the rifle and just want to remedy the situation.
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Rich,
Not a recommendation but I lifted my barrel to be aligned with the reservoir and the clipping stopped, my accuracy has increased dramatically and I may even be able to enter the 10m contest now!
I.ve had a clipping issue for a few weeks...it hits end cap at 5 o'clock (see pic below) what concerned me was shroud alignment and to tight a tolerance (.25" opening in end cap IMO). My Avenger, also a .22 has a .375 opening in the end cap with no issues.. I have not removed or disturbed shroud as I also have a leak that lowers fill pressure 800 psi in 4 hours...I'm getting ready to start the warranty process...
I have read on other forums that some have drilled out end cap and cured their issue....I do not want to do that because of the leak.
https://u.cubeupload.com/crazyhorse4/IMG0574.jpg
I like the rifle and just want to remedy the situation.
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On the DAR, there is an o ring holding the barrel to the clamp and two grubs holding the clamp to the reservoir, its tight and there is zero movement.
The shroud support that slides on the end of the barrel. How loose is it on the barrel? And how loose is it in the shroud? I suspect bother are a little on the loose side causing your problems.
Sorry, I should have said in the shroud. The thing that goes on the end of the barrel. Its most likely a loose fit to barrel and shroud.
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Snug this up if you can. Maybe one wrap of Teflon tape on the barrel. And one wrap of scotch tape around the od of the spacer.
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Rich,
Not a recommendation but I lifted my barrel to be aligned with the reservoir and the clipping stopped, my accuracy has increased dramatically and I may even be able to enter the 10m contest now!
I.ve had a clipping issue for a few weeks...it hits end cap at 5 o'clock (see pic below) what concerned me was shroud alignment and to tight a tolerance (.25" opening in end cap IMO). My Avenger, also a .22 has a .375 opening in the end cap with no issues.. I have not removed or disturbed shroud as I also have a leak that lowers fill pressure 800 psi in 4 hours...I'm getting ready to start the warranty process...
I have read on other forums that some have drilled out end cap and cured their issue....I do not want to do that because of the leak.
https://u.cubeupload.com/crazyhorse4/IMG0574.jpg
I like the rifle and just want to remedy the situation.
Thanks. I realized the alignment issue with the barrel/shroud but with the leak I have no choice but to send it back, especially with the news about the new "O-rings"...I'm just glad I was patient and did not rush the claim a few weeks ago.
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David, after your explanation it sounds like the barrel isn't straight, too bad you couldn't remove it and roll it across a sheet of glass or chuck it up in a lathe. I watched a YT video years ago on a Marauder barrel that was way off and the guy was bending it back straight in a lathe and checking it with a meter.
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Rod,
LOVE IT!! Thanks man, it's the simple stuff I completely wiff on!
Snug this up if you can. Maybe one wrap of Teflon tape on the barrel. And one wrap of scotch tape around the od of the spacer.
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I wish I could too but I need an airgun that shoots (or ill go crazy!!) so I have to honor the terms of the warranty for now. For PB's, I have in a very literal way, smacked a barrel against a tree to straighten it out and then check for runout on my lathe. I have a magnetic based dial indicator good to 0.0001 so its pretty easy to test if I could just get it out of the gun! ;)
David, after your explanation it sounds like the barrel isn't straight, too bad you couldn't remove it and roll it across a sheet of glass or chuck it up in a lathe. I watched a YT video years ago on a Marauder barrel that was way off and the guy was bending it back straight in a lathe and checking it with a meter.
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Here is a question for the brain trust here: How often do I clean the barrel? With PB's I clean it after every session. With airguns, I only patch and never scrub and haven't done a polish with Flitz as I normally do.
This barrel has about 500 pellets through it so far, I would think I would have a good seasoning by now...
As soon as i received mine. Went after it good with a bronze brush and goo gone. Lots of nasty gunk in the barrel from the factory. Then went after it with jb bore paste. Stepped down to mothers mag polish and finished with Johnsons paste wax. I do this to all my new guns. My dar is a tac driver.
Thing is you have to remove the barrel to do so.
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I dont have any goo-gone (causes breathing issues with my wife), is there another facsimile?
Here is a question for the brain trust here: How often do I clean the barrel? With PB's I clean it after every session. With airguns, I only patch and never scrub and haven't done a polish with Flitz as I normally do.
This barrel has about 500 pellets through it so far, I would think I would have a good seasoning by now...
As soon as i received mine. Went after it good with a bronze brush and goo gone. Lots of nasty gunk in the barrel from the factory. Then went after it with jb bore paste. Stepped down to mothers mag polish and finished with Johnsons paste wax. I do this to all my new guns. My dar is a tac driver.
Thing is you have to remove the barrel to do so.
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I have been using WD-40 to clean my barrels for years, works very well. Have also used toothpaste and a nylon bristle brush on a jag to do a light polish as well as clean sludge from the barrel, just dip the brush coated in toothpaste into some baking soda and go to town. You'll be surprised how much gunk comes off with a little toothpaste and then clean patches soaked in WD-40. Add some paste wax when done and your barrel will stay clean longer.
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A long over due follow up post on the DAR.
After the barrel change, there was an air leak, I tapped the hammer spring housing with a leather hammer and it took air but overnight, it all leaked out so I had to go inside the gun...
I have completely stripped all components down to sub assemblies, changed out the TP o-ring but have left the rest alone for now. I tightened up ther four hole poppet spring cap down 1 turn and checked it for operation/binding etc. called it good and turned the regulator screw down to be flush with the regulator face.
I reassembled the gun and it held air with no help from a tap to the rear end. I pumped it up to 21MPa and dry fired a few times to clear the system, pumped it back up to 21MPa and left it overnight. It held all air and was still at 21MPa after 24 hours. I loaded all three mags and set up a 10m/24 bull target and started to drop lead on bullseyes.
Without the use of the chrony, I estimated from pellet drop that it fell off the reg at 12MPa after 62 pellets. I was able to get another 10 pellets on the bullseye on and off until shot 72 when the placement fell an inch or more.
What's next? I am going to call Joe on Tuesday and have him send me another hammer spring, or at least get the wire size and dimensions. I will then cut a coil off the hammer spring and see if my shot count increases. I may also get a chance to shoot thru the chrony on Monday as it will be in the 40s!! Then I will know for sure when it falls off the reg. I am aiming for 90 shots on the reg, lets see if I can get it there?
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A long over due follow up post on the DAR.
What's next? I am going to call Joe on Tuesday and have him send me another hammer spring, or at least get the wire size and dimensions. I will then cut a coil off the hammer spring and see if my shot count increases. I may also get a chance to shoot thru the chrony on Monday as it will be in the 40s!! Then I will know for sure when it falls off the reg. I am aiming for 90 shots on the reg, lets see if I can get it there?
David
What caliber is your DAR?
I looked thru the thread but did not see it.
Thanks
Ed
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Good gravey! You are right, it's a. 22, Ed. :o
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Good gravey! You are right, it's a. 22, Ed. :o
Thanks, David
Looking forward to your chrony results.
Ed
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I am thinking about a replacement barrel, LW has a barrel for 115, do they come chambered?
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If you mean the leade it did not on mine, but that was 6 years ago....
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Did you just use a reamer for the lead?
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My friend has a lathe. We swap stuff for favors. ;D
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Gotcha! I have a couple lathes but was wondering how the lead was cut?
My friend has a lathe. We swap stuff for favors. ;D
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A reamer at 0.1mm over the nominal diameter works well. So for example a 4.6mm reamer for .177, 5.6mm reamer for .22, 6.5mm reamer for .25.
Ream to a depth that accommodates the skirt when seated but allows the head to move into the rifling. In most cases that means you’re reaming to a point just beyond the barrel port.
Then clean up the freshly-reamed area with a suitable abrasive regimen. That could be wet/dry sandpaper on a dowel or a rubberized abrasive bit (e.g. Cratex point) or your method of choice. Of particular importance is the step up into the rifling…the finish left by the tip of the reamer will be somewhat rough. Blend this area to a smooth transition so pellets can gently swage into the rifling. A sharp edge at any of the lands is apt to score the pellet and perhaps cause it to seat crooked and that’s no bueno.
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Gotcha! I have a couple lathes but was wondering how the lead was cut? My friend has a lathe. We swap stuff for favors. ;D
I left it with him after our match at his place...I'm sure he used a reamer but don't know details (after 6 years)...
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FANTASTIC!! Thank you, though one last question, what pellet should I use to measure the insertion? I use CPHP most of all so where the probe ends
and subsequent skirting hangs into the lead but is in contact with the lands is what you are saying? A reamer at 0.1mm over the nominal diameter works well. So for example a 4.6mm reamer for .177, 5.6mm reamer for .22, 6.5mm reamer for .25.
Ream to a depth that accommodates the skirt when seated but allows the head to move into the rifling. In most cases that means you’re reaming to a point just beyond the barrel port.
Then clean up the freshly-reamed area with a suitable abrasive regimen. That could be wet/dry sandpaper on a dowel or a rubberized abrasive bit (e.g. Cratex point) or your method of choice. Of particular importance is the step up into the rifling…the finish left by the tip of the reamer will be somewhat rough. Blend this area to a smooth transition so pellets can gently swage into the rifling. A sharp edge at any of the lands is apt to score the pellet and perhaps cause it to seat crooked and that’s no bueno.
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No problem. What I was trying to convey is to ream the leade such that when a pellet is seated, its head is engaged in the rifling but the skirt is not.
For a gun with pin probe like the DAR, pellets will seat to a slightly different depth depending on the particulars of the skirt geometry. Meaning, contrasted against a hollow probe which seats the pellet by the skirt perimeter. The distinction is worth noting but for the most part, there is enough similarity that you can generally take a couple of pellets in and around the weight range you expect to use and seat them to gauge about how deep you want to run the reamer.
For your .22, the Crosmans and JSB 18.1gr (or 15.9gr) would be my recommendations.
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Thank you, that is what I was trying to articulate (and doing so poorly) with you about the depth. I also did settle on those three pellets, others just dont pattern well from my DAR. With the .25 coming, I did order a 22g NOE mold today, I love the molds but..... :-X
No problem. What I was trying to convey is to ream the leade such that when a pellet is seated, its head is engaged in the rifling but the skirt is not.
For a gun with pin probe like the DAR, pellets will seat to a slightly different depth depending on the particulars of the skirt geometry. Meaning, contrasted against a hollow probe which seats the pellet by the skirt perimeter. The distinction is worth noting but for the most part, there is enough similarity that you can generally take a couple of pellets in and around the weight range you expect to use and seat them to gauge about how deep you want to run the reamer.
For your .22, the Crosmans and JSB 18.1gr (or 15.9gr) would be my recommendations.
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Here is some info of the inside skirt depths of numerous 22 cal pellets I have measured,
Inside depth of skirt, from the bottom of skirt to pellets inside waist, the pin bolt probe pushes against.
Shortest
Benjamin Super Point =============----.052"
JSB Match Exact Jumbo Monster Diabolo==----.058"
JSB Match Ultra Shock Heavy Diabolo====---.064"
JSB Match Exact Jumbo Heavy Diabolo ===---.065"
Skenco Ultrashock Hollow Point========---.072"
Benjamin Hollow Point =============---.076"
Crosman Premier HP ==============---.084"
Benjamin Pointed Expanding =========---.094"
Benjamin Domed Magnum ==========----.096"
Crosman Premier Piranha ===========---.098
JSB Match Diabolo Straton Jumbo ======---.100"
Kodiak Tapered Dome=============----.108"
H&N Baracuda Match =============----.108"=5.51 Head Dia
JSB Match Exact Jumbo Diabolo =======---.112"
H&N Baracuda Match==============---.112"=5.53 Head Dia
Gamo Red Fire =================----.114"
NOE .217 Hunter================----.130"
NOE .217 Mag Hunter =============---.133"
Skenco Newboy Hollow Point =========---.136"
H&N Field target Trophy ============---.142"=5.54 Head Dia
Skenco Newboy Junior=============----.144"
H&N Field Target Trophy============----.154"=5.55 Head Dia
Ruger Superpoint================----.170"
Daisy HP (Spanish made)===========----.175"
Gamo Platinum==================---.200"
Longest
Shortest Skirt/base depths = .052"
Longest Skirt/base depths = .200"
Difference of .148" in skirt depths.
I will update this data base, when I find more pellets that are not included.
HTH's
Don
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Don, You sure seem to spend a lot of time looking up those skirts! :o :P ;D
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It’s okay, he has a signed consent affidavit from each of them.
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Thanks Paul/Jason
ROTHFLMAO..................at my age you take it ANY way you can find it.......... ;) ;D
I can look, but CAN'T touch.................... ;D
Back to regular programing............... ::)
Thanks,
Don
Don, You sure seem to spend a lot of time looking up those skirts! :o :P ;D
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Someone posted a link to some Czech or Russian barrels yesterday, I think I might drop 70 Euro on one of those fancy if that works in my DAR. They have a 1 in 14 twist that looks like a great candidate for me!
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I have the chrony results from todays session. There is some very interesting data below starting at shot #30 with a rise to 841 fps. Then again at shot #33 as it rises to 870 fps then falls off the regulator at shot #54.
Certainly not what I was hoping for...
Created: 02-27-2021 12:37:00 PM
Description: .22 DAR
Temp: 36 °F
BP: 1014.00 inHG
Shots
# FPS FT-LBS PF
57 808 0.00 0.00
56 812 0.00 0.00
55 822 0.00 0.00
54 824 0.00 0.00
53 831 0.00 0.00
52 834 0.00 0.00
51 844 0.00 0.00
50 842 0.00 0.00
49 832 0.00 0.00
48 836 0.00 0.00
47 852 0.00 0.00
46 858 0.00 0.00
45 853 0.00 0.00
44 ERROR 2
43 870 0.00 0.00
42 868 0.00 0.00
41 856 0.00 0.00
40 864 0.00 0.00
39 867 0.00 0.00
38 863 0.00 0.00
37 854 0.00 0.00
36 850 0.00 0.00
35 847 0.00 0.00
34 840 0.00 0.00
33 832 0.00 0.00
32 820 0.00 0.00
31 827 0.00 0.00
30 841 0.00 0.00
29 833 0.00 0.00
28 837 0.00 0.00
27 834 0.00 0.00
26 836 0.00 0.00
25 837 0.00 0.00
24 834 0.00 0.00
23 838 0.00 0.00
22 827 0.00 0.00
21 828 0.00 0.00
20 829 0.00 0.00
19 829 0.00 0.00
18 833 0.00 0.00
17 835 0.00 0.00
16 831 0.00 0.00
15 832 0.00 0.00
14 833 0.00 0.00
13 828 0.00 0.00
12 835 0.00 0.00
11 826 0.00 0.00
10 827 0.00 0.00
9 835 0.00 0.00
8 834 0.00 0.00
7 833 0.00 0.00
6 835 0.00 0.00
5 836 0.00 0.00
4 833 0.00 0.00
3 832 0.00 0.00
2 836 0.00 0.00
1 830 0.00 0.00
Average: 837.38
StdDev: 13.15
Min: 808
Max: 870
Spread: 62
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The velocity rise near the end of the string is an indication you have the hammer spring tension set too light for the regulator's setpoint. If you want it to have a gentle rolloff, dial the HST to about 97% of the maximum velocity. Doing so will reduce the shot count but will improve consistency.
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Like Jason suggested....dial it up or turn the reg down some. It came off the reg about shot 33.
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Thanks guys! That's the info I was looking for. I would like to add that the poppet spring has also bee tightened up some to fight off leaking (didn't work, still loosing 500 psi a day) so I'll return that to it original setting and then turn the hammer spring back in 1/2 turn to factory specs and hit the chrony again.
Looks like I will pull the reg at that time and replace the rings (Joe could not give me a part number but I will parse that information from the ring/s I pull) and will wait for that new barrel from Joe and decide which shoots better but after yesterdays session (about 50 shots), I may keep the old barrel. I will show you all the results from 65 yards in my next post.
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My plans for yesterday afternoon were dashed when I picked up the DAR to try a few pellets and noticed the gauge read zero, it had leaked down to empty overnight.
I shifted gears and decided to tear the entire gun down and figure out what was going on. I replaced all the O-rings that were in the kit except for the smallest of them, I have no idea where that teeny tiny one goes!
There were a few issues, flat O-rings on the regulator, flat O-rings on the plugs at both ends of the air reservoir, gauge and poppet side both.
The poppet looked good to the eye until I put a loupe on and noticed that it had some wrinkles on one side of the face, I chucked it up in my lathe and refaced it with a 1 degree chamfer. Putting it back in, I had a severe leak through the poppet still.
I am ended up simply chucking the poppet stem in a small drill and faced the popet by pulling it back into the poppet seat while turning the drill slowly, a poor man's version of burnishing.
That seems to work well, it's holding 3,000 PSI overnight with no movement on the gauge. The good news is that I can now disassemble and reassemble the DAR with a blindfold! I think I pulled it apart no less than a dozen times last night.
In a related issue, I couldn't get more than a thousand pounds in the gun off the hand pump once I had the DAR fixed, turns out the hand pump was all gunked up with a junk and had to rebuild the hand pump last night as well. No O-rings were used, just a good cleaning to get seals on both ends working once more. Hopefully I will get some shots down range tonight.
The .25 is scheduled to arrive monday, we will see if its holding air. It will be fun to see what the cast pellets do, I have low expectations so as long as they will hit 1/2" groups at 20y, they will be good for close paper punching.
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Glad you got your leak worked out.
I have to do that with mine now. It's leaking 1000psi a night.
Still shoots great but its leaking pretty bad now.
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My plans for yesterday afternoon were dashed when I picked up the DAR to try a few pellets and noticed the gauge read zero, it had leaked down to empty overnight.
I replaced all the O-rings that were in the kit except for the smallest of them, I have no idea where that teeny tiny one goes!
There were a few issues, flat O-rings on the regulator, flat O-rings on the plugs at both ends of the air reservoir
That seems to work well, it's holding 3,000 PSI overnight with no movement on the gauge.
The .25 is scheduled to arrive monday, we will see if its holding air. It will be fun to see what the cast pellets do, I have low expectations so as long as they will hit 1/2" groups at 20y, they will be good for close paper punching.
Good luck with the "kit" o-rings....
Is the .25 cal a new rifle ?
Rich
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Glad you got your leak worked out.
I have to do that with mine now. It's leaking 1000psi a night.
Still shoots great but its leaking pretty bad now.
I'm hoping to get a section of Ti rod ground to the same dimensions as the poppet rod and will mount a delrin seat in it so I can get a better seal. The shavings indicate the poppet in the gun is delrin but the design is awful. The poppet edge was so small (sharp) that dust or a hair could block it open and I think swarf got into the face giving it the half circle dent.
The seat appears to be brass but I could not remove it as the ball bearing for the bleed screw, degassing post was over tightened and crimped the housing.
Funny but that was the only right screw on the gun.
Yes, the .25 is brand new, new orings and coming from DAR.
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I shoot Exact Kings in my Marauder .25 cal...25.39 GR...they also work good in the wind. Think they work well in most rifles...
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I shoot Exact Kings in my Marauder .25 cal...25.39 GR...they also work good in the wind. Think they work well in most rifles...
I have my first pellet mold from NOE that drops 25gr pellets, I hope they shoot well but with a full .25 meplat, I think distance will be an issue.
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Make some as long as you can even if you must handload without magazine...think you will need about 860 FPS for 100 yds..
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Make some as long as you can even if you must handload without magazine...think you will need about 860 FPS for 100 yds..
The NOE mold only allows for skirt depth, not overall length.
I'll be watching for the domed version of the 30gr pellet.
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The NEW DAR .25 Eats a lot of air, I start at 200 bar and shoot until 100 bar and refill. I get exactly 20 shots or 2 magazines for every top-up.
I get 900 fps with the 25gr for 45 fpe. That is a nice number for pesting as the .22, 14.3gr flying at 850 fps make 22.9 fpe and that is OK for most of my needs but other critters really need 45 fpe for a quick kill. I would like 50 fpe for yotes and other same sized critters but dont know what this gun has in it still since it feels pretty wide open at this point.
I removed the barrel and popped out the probe o ring, gave it a good scrub with Ed's Red then followed up with Goo-Gone. Greased up the o ring and replaced it, pulled the trigger and sear, polished them up hit the contact points with moly grease, reassembled and started running pellets through it.
Nothing fantastic as its seasoning, minute of yote head at 50y to start then I changed gears, replace the pins in the mold, went from the 22gr pellets to the 25gr pellets and the groups started to close up. I would say I ma closing to minute of ground hog now and I think another tin will bring me down to squirrel head at 50y.
With the new compressor, fills are simple, both of the guns are holding air with no drop. The next thing is a scope. I am looking at a 4-24x50, FFP for wet work.
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My Marauder .25 cal .25.3 gr is hitting at 42 ft lbs from the Green Mountain barrel. It was the first time I heard a squirrel squeal when hit and I have shot a bunch of squirrels in .22 cal.
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My Marauder .25 cal .25.3 gr is hitting at 42 ft lbs from the Green Mountain barrel. It was the first time I heard a squirrel squeal when hit and I have shot a bunch of squirrels in .22 cal.
How many shots before falling off the reg? I did some chrony work today and my DAR drops off at 18 shots. >:(
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My Marauder .25 cal .25.3 gr is hitting at 42 ft lbs from the Green Mountain barrel. It was the first time I heard a squirrel squeal when hit and I have shot a bunch of squirrels in .22 cal.
How many shots before falling off the reg? I did some chrony work today and my DAR drops off at 18 shots. >:(
Time to start tuning it then. Reg pressure is most likely set too high hogging air.
I believe Jason has his tuned at 40 fpe for something like 30 shots? Maybe he'll chime in.
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My gen1 turned in 31 shots at just under 45fpe inside a 4% ES
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=6030)
Nothing special done to improve efficiency. Just adjusted hammer spring tension to the velocity knee.
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There you go David. Thats with the heavies. They usually run 80-100 fps slower than the 25 grain jsb. So you should be able to get close to 30 shots at 850 with some tuning.
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My Marauder .25 cal .25.3 gr is hitting at 42 ft lbs from the Green Mountain barrel. It was the first time I heard a squirrel squeal when hit and I have shot a bunch of squirrels in .22 cal.
How many shots before falling off the reg? I did some chrony work today and my DAR drops off at 18 shots. >:(
My Marauder is not regulated...but averages 860 FPS.....across 20 shots.
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Since I am a rank n00b with PCP's, I need some help with figuring out where to start with tuning the .25 DAR.
I have read Knifemakers, Bob's posts and others threads but they all seem to have a different starting point and none speak of the DAR platform specifically. I also need to find a 1 sentence synopsis of what the "velocity knee" is.
Chrony is set up and ready for testing, I have a bottle filled and ready to overcome a leaky poppet should that arise and the time to work all day on it if necessary.
Step 1 is to do the same as the DAR .22, take it apart and see what they have written on the reg body and adjust the screw to be level with the body, adjust the hammer spring cap to be even with the body, reassemble and shoot a string.
Trigger work is done, feels very nice, barrel was cleaned, cocking arm has been lubed, moves freely now. Lets get started!
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The velocity knee is simply 95 - 97% of the maximum velocity, by way of adjusting the hammer spring tension. It is favorable for consistency and produces good but not great efficiency.
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Read this David...
https://www.gatewaytoairguns.org/GTA/index.php?topic=74919.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=74919.0)
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Read this David...
https://www.gatewaytoairguns.org/GTA/index.php?topic=74919.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=74919.0)
Rich, I have read that thread by Bob a few times and it seems that my starting place with the hammer spring preload is not the issue as that is what I did when I got the gun but nothing changed at all. I may have to find a softer spring but first, I am tearing the gun down to the reg and adjust it like I did the .22.
Here is the chrony string from this morning, 25.5g WC, chrony at 1 foot, 65F, starting pressure 210 bar, ending pressure 100 bar, 20 shots. Looks like it fell off on shot #14. BTW- the speed is right where I want it at 860.
1-862
2-861
3-862
4-860
5-860
6-858
7-859
8-865
9-862
10-864
11-862
12-849
13-862
14-861
15-853
16-837
17-831
18-815
19-802
20-798
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When I got my Marauder .25 10 years ago it came from factory shooting 820 or so...I made adjustments to get it to 860 and left it and have not touched it since. Very accurate and just 1.25" group at 100 yards...Just received my new compressor yesterday and now I can get things done a little quicker and get off the hand pump. It is the Umarex Readyair....$529 from AOA.
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If you screw the hammer spring all the way in or all the way out, it stays in the 860's?
Here. Do this.
Back the hammer spring all the way out. Take a shot over the chrono. Record the fps. Turn it in one half turn, shoot it over the chrony. Record the fps. Keep going half turns and recording until the hammer spring is maxed out. Post the numbers up for us. And the pressure in the tube when it falls off the reg.
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I disassembled the gun and turned in the regulator screw two full turns, it is now shooting approximately 802 FPS. The DAR does not allow for hammer spring adjustments while in the stock, I will have to naked frame shoot it while messing with the hammer spring. The good news is that I was able to get two full magazines down range without falling off the regulator.
Be right back....
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OK, 3-1/2 turns from all the way out to all the way in and it would no longer cock.
1-819
2-812
3-814
4-805
5-809
6-810
7-808
Higher velocity the further out the hammer spring was.... Hmmmmm. ???
Is shot #4 with 805 significant?
Never came off the reg.
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I turned the reg back to factory settings, spun the hammer spring cap all the way out and with the bolt uncocked, turned the cap in until it contacted the spring for a starting point. I got 2 more shots and 1 more turn of the cap this way. Starting pressure was 21MPa and end pressure was 18MPa. 9 shots taken, trigger failed to catch sear on shot #10. The results are below.
My initial impression is to do 1/4 turns and see if there is more useable data.
1-630
2-662
3-719
4-754
5-786
6-860
7-908
8-931
9-941
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There we go! A quarter turn on the reg is a 30 bar swing....if not more. 2 turns would most likely make it inoperable.
Dinner time....will try and help some later.
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Ok....forget about the word "KNEE" and think plateau.
From your shot string...you were getting very close to your velocity plateau. Or top of your knee. If you had a little more hammer spring adjustment, your velocity woud have climbed another 5-10 fps. At that point,, more hammer spring would not gain any more velocity.....just make more noise and waste air. That would be the tip of your knee...or plateau.
Sooo... what your string is showing. Is your reg is set higher than your hammer spring has the energy to reach.
Lets say your hammer spring had enough energy to reach the plateau of 950fps . We like to tune to 95-97% below the max fps. Which is in the neighborhood of 30fps. So for your current reg setting.... your gun would be optimally tuned to 920 fps.
Now.... to set your gun up to shoot at 850 fps. You need to lower the reg until its maximum velocity peeks out at 880-885 fps. And then drop the hammer spring back until your shooting your 850 target. That's where you'll get your best shot count for that velocity.
Hope that helps some. Others can explain it better.
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Ok....forget about the word "KNEE" and think plateau.
From your shot string...you were getting very close to your velocity plateau. Or top of your knee. If you had a little more hammer spring adjustment, your velocity woud have climbed another 5-10 fps. At that point,, more hammer spring would not gain any more velocity.....just make more noise and waste air. That would be the tip of your knee...or plateau.
Sooo... what your string is showing. Is your reg is set higher than your hammer spring has the energy to reach.
Lets say your hammer spring had enough energy to reach the plateau of 950fps . We like to tune to 95-97% below the max fps. Which is in the neighborhood of 30fps. So for your current reg setting.... your gun would be optimally tuned to 920 fps.
Now.... to set your gun up to shoot at 850 fps. You need to lower the reg until its maximum velocity peeks out at 880-885 fps. And then drop the hammer spring back until your shooting your 850 target. That's where you'll get your best shot count for that velocity.
Hope that helps some. Others can explain it better.
Rod, freaking awesome!!!! That's what I was looking for. I will pull her down tomorrow and turn the reg in 1 turn, Ill back out the HS to the same place and start another string.
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1 turn is a massive amount for a reg adjustment. Just go a quarter turn in. Then do a string like you did above with half turn adjustments with the hammer spring.
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1 turn is a massive amount for a reg adjustment. Just go a quarter turn in. Then do a string like you did above with half turn adjustments with the hammer spring.
Roger that!
Thank you again.
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;) David this is why I became a member here and also why I love to see new members getting the help they need without giving up on the hobby/obsession
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;) David this is why I became a member here and also why I love to see new members getting the help they need without giving up on the hobby/obsession
AMEN, Don!
Simple, straight to the point, empathetic not apathetic.
I think I'll take the time to use the good camera and document the parts as I disassemble the gun.
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That's what I do whenever I take a new AG apart for the first time. At each step in the take down several pictures for reference, that way the reassembly is much easier. ;)
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That's what I do whenever I take a new AG apart for the first time. At each step in the take down several pictures for reference, that way the reassembly is much easier. ;)
I did do that but poor lighting and just assembly pictures for an aid in putting it back together, this time I want to document individual parts with the Nikon.
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Ok....forget about the word "KNEE" and think plateau.
From your shot string...you were getting very close to your velocity plateau. Or top of your knee. If you had a little more hammer spring adjustment, your velocity woud have climbed another 5-10 fps. At that point,, more hammer spring would not gain any more velocity.....just make more noise and waste air. That would be the tip of your knee...or plateau.
Sooo... what your string is showing. Is your reg is set higher than your hammer spring has the energy to reach.
Lets say your hammer spring had enough energy to reach the plateau of 950fps . We like to tune to 95-97% below the max fps. Which is in the neighborhood of 30fps. So for your current reg setting.... your gun would be optimally tuned to 920 fps.
Now.... to set your gun up to shoot at 850 fps. You need to lower the reg until its maximum velocity peeks out at 880-885 fps. And then drop the hammer spring back until your shooting your 850 target. That's where you'll get your best shot count for that velocity.
Hope that helps some. Others can explain it better.
Rod, freaking awesome!!!! That's what I was looking for. I will pull her down tomorrow and turn the reg in 1 turn, Ill back out the HS to the same place and start another string.
That explanation IS certainly awesome! And here I thought Rod was only known for the Elvis-like sideburns of his cool avatar... ;D
Applicable for tuning most all regulated guns, Thanks!