Author Topic: Calling all 25 cal marauder REGULATED guns (Read 52713 times - 1 votes)
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Sfttailrdr46 · « **Reply #20 on:** October 31, 2016, 10:21:05 AM »

Frank sometimes threads will go right off the chart others just live forever kind of like a 1/4 mile drag race and others are more like the Paris to Dakar race, there are threads on here that keep getting resurrected because new members will discover them and pose a question that has not addressed but the GTA will always be a wealth of information for any member that wants to learn about all things AG related. Also there are certain aspects of this thread that are always going to be pertinent for any PCP AG that a member plans to mod or tune themselves whether it is a.25 Marauder or a .25 Air Arms S510 .25 that needs to be regulated

Dairyboy · « **Reply #21 on:** October 31, 2016, 10:32:42 AM »

I'm "working" on mine at the moment. Been waiting to test the tune out but only been raining every day this last 3 weeks. Starting today for the next 10 days looks like we only have 1 chance of rain so hopefully I can get my 40fpe 40 shot tune done

WiseGuy · « **Reply #22 on:** October 31, 2016, 11:01:40 AM »

Also interested in the 4040 tune with the regulator. Question, is there a US supplier of the Huma Regs?

triggertreat · « **Reply #23 on:** October 31, 2016, 12:40:20 PM »

Quote from: mobilemail on October 31, 2016, 08:51:53 AM

I'm watching because I'm not only interested in the 4040, but I'm also thinking what this could do to transform a .22 mrod. 6030 (60 shots @ 30fpe regged)?

I'm with you on the 22. I've reached a 60/29.6/4%, 50/33/4%, 46/34.2/4%, 40/30/2% and a 30/30/1.36% unregulated, but am about to rebuild to go further. Just trying to keep up but if I can't, a regulator maybe in my future if these experts can show significantly better numbers regulated in this journey.

rsterne · « **Reply #24 on:** October 31, 2016, 01:04:57 PM »

Regulators are perfect when you are tuning a PCP for low to medium powered tunes (relative to what the gun is capable of).... not so much for high power tunes.... The reduced pressure makes it difficult to even get to high power, and finding space for a large enough plenum makes the task even harder.... shorty's 40 FPE tune is an interesting one.... It shows graphically what happens when you reduce the hammer strike on a regulated PCP that is set up for more power (ie higher setpoint pressure) than you want/need.... You get two immediate effects.... First, you get great efficiency, because you are using tiny sips of air at a higher pressure than you need to do the job.... Second, below the setpoint, the velocity increases.... If shorty continued shooting until the power dropped back to just under 40 FPE where it started, he might even get 50 shots.... It would be interesting to see how high the velocity went before peaking, the graph shows no sign of turning back down at 40 shots....

There is nothing wrong with tuning a regulated PCP this way, and if you want the flexibility of being able to crank the power up, it's a great way to dial down the power.... For some uses, it would be problematic, such as a sub 20 FPE tune for FT.... If the velocity above the setpoint was just under what was allowed, the gun would be shooting too hot at the end of the string.... That would make the string a maximum of 36 shots.... A better solution in that case would be to reduce the setpoint pressure and hammer strike, to tune to the knee of the curve instead of the downslope, where the tune is now.... Then you could watch the pressure guage and know you weren't over the 20 FPE mark, rather than trusting on counting shots.... If the upturn in velocity at the end of the string is unimportant, however.... it's a great tune, and gives you the ability to dial the power back up if required.... something you couldn't do if you used a lower setpoint pressure....

Bob

shorty · « **Reply #25 on:** October 31, 2016, 04:53:31 PM »

I know I said 25 cal marauder but, take a look at this mobilemail.
http://www.gatewaytoairguns.org/GTA/index.php?topic=103892.0
Gen2 .22cal
Fill 2250 and end pressure 1250
Huma with gauge port set at 1550
Same mods as my 25 except .168" porting.

42 shots on regulation with just a 2250 fill. I shot a few off regulation. This gun is now tuned for 24/25fpe (14.3 grain) for 93 shots on regulation and an additional 10 to 20 off all under 2% ES from a full 3000 psi fill.

Bob make a solid point about tuning to the knee for the consistent shots off regulation. It's all how you set up the reg set point and hammer spring strength. Running a knee chart tells the tail of where the gun likes to be tuned to get the additional shots off regulation.

shorty · « **Reply #26 on:** October 31, 2016, 05:01:54 PM »

Almost forgot,
Dairyboy, hurry up.

. I can't wait to see your numbers.

And

I know there are other guys out there with 25 cal regulated Mrod's. Please post up some numbers and the mods that you have done to get were your at.

PBguns · « **Reply #27 on:** October 31, 2016, 05:18:59 PM »

Link to what I have done to my .25:

http://www.gatewaytoairguns.org/GTA/index.php?topic=109935.0

Couple strings to share:

40 shots:

56 shots (falling off reg):

Dairyboy · « **Reply #28 on:** October 31, 2016, 05:24:26 PM »

Quote from: shorty on October 31, 2016, 05:01:54 PM

Almost forgot,
Dairyboy, hurry up. . I can't wait to see your numbers.

Lol I had about 30min to work on it today and had horrible consistency and accuracy! Was shooting 860 then some would drop to 800 and some to 780 then back up and every time was 10secs or so between the shots. Have no clue what's causing the problems as the hammer is running super smooth but will hafta tear it down again and figure out what the problem is now.

shorty · « **Reply #29 on:** October 31, 2016, 05:39:33 PM »

Just thought about it.

Bob's comment about lowering the reg set point. It is valid although, what PB guns did is run a smaller transfer sleeve than I did which reduces the power slightly. It does something else though as well. It moves that magical point of getting shots off regulation at the power level your looking for.

So don't think you have to pull the gun apart and re-adjust the reg set-point to run in YOU'RE sweet spot. This is supper critical because the thought process a while back was to open the porting as much as you can to get power and efficiency at lower pressure when installing a regulator.

In my case with .196" porting, a quick change to .168" porting should mimic PBguns shot string but, not allow me to hit over 50 fpe on regulation. This is something that should not be missed.

PBguns · « **Reply #30 on:** October 31, 2016, 05:49:11 PM »

Quote from: shorty on October 31, 2016, 05:39:33 PM

Just thought about it.

Bob's comment about lowering the reg set point. It is valid although, what PB guns did is run a smaller transfer sleeve than I did which reduces the power slightly. It does something else though as well. It moves that magical point of getting shots off regulation at the power level your looking for.

So don't think you have to pull the gun apart and re-adjust the reg set-point to run in YOU'RE sweet spot. This is supper critical because the thought process a while back was to open the porting as much as you can to get power and efficiency at lower pressure when installing a regulator.

In my case with .196" porting, a quick change to .168" porting should mimic PBguns shot string but, not allow me to hit over 50 fpe on regulation. This is something that should not be missed.

I agree with shorty.

Half of me is thinking "if I change the reg setpoint down to 1800psi (130bar)" I could take that 40 shots on regulation and extend it.
The other half of me (which I'm currently siding with) thinks that will change more than just shot count.

I'm not sure I want to loose this tune yet.

Dairyboy · « **Reply #31 on:** October 31, 2016, 06:31:36 PM »

My problem is I've never had the gun unregulated. I have no idea what numbers or strings I can get from it. So I think what I need to do is unregulate it and then tune it from there and find out where I need to do my set point from.

shorty · « **Reply #32 on:** October 31, 2016, 06:40:12 PM »

Dillion,
I am not sure if you have that SSG in there or not but, try and run a knee curve.

Adjust the SSG or hammer spring to get 30 fpe or so and then turn up the power 1/4-1/2 hammer spring turns to see when it flattens and drops off when on regulation. keep note of where the adjustments so that you can re-adjust to just before the peak of the curve.

This will get you your max FPE with a few shots off regulation.

After all that, you can make a sound decision on where to go. Piece of cake with my spring but maybe a little bit more work with an SSG.

Ozarkairgunner · « **Reply #33 on:** October 31, 2016, 08:58:34 PM »

Hey guys, hope you don't mind me jumping in here and hopefully I'll be able to contribute more soon. I have the newer huma regulator design with the gauge port made into it ordered and on the way, should be here this weekend. I get what the pleume space is and why it's needed, I don't understand how to measure for it and to determine how much you need to achieve the proper power, any help would be appreciated.

Motorhead · « **Reply #34 on:** October 31, 2016, 09:44:10 PM »

Quote from: wiseguy on October 31, 2016, 11:01:40 AM

Question, is there a US supplier of the Huma Regs?

TRENIER OUTDOORS ..... http://trenieroutdoors.com/gear/huma-airgun-regulators/

shorty · « **Reply #35 on:** October 31, 2016, 10:19:35 PM »

CJ,
The reg your getting is the same as PBguns and mine. You can't do much to increase the plenum unless you open it up and bore it out. Nothing I wanted to do and wouldn't recommend. Heck, is was 120 bucks. It better have worked.

I have been collecting some data on your comments for power though using this newer style Huma 25 cal with gauge port regulator. Here's a table based on my 25 cal,my spreadsheet, along with some of the data coming out from the rest of the guys in regards to this particular regulator and pressure settings for .187" and .161" porting. These are just my numbers and take as a grain of salt but, they seem pretty close to the max powers at those pressures.

rsterne · « **Reply #36 on:** October 31, 2016, 10:34:53 PM »

Makes perfect sense, and 100% inline with theory.... If you plot out those numbers you get straight lines, just as you should.... Maximum FPE should be proportional to pressure, if you have constant port diameter, caliber, and bullet weight.... At 2400 psi you should get 50% more FPE than at 1600 psi....

PS shorty, the 26 FPE at 1600 is incorrect....

Bob

shorty · « **Reply #37 on:** October 31, 2016, 10:37:31 PM »

Almost forgot and it's important.

If you plan on regulating,plan on working the stock valve by opening up the exit port on the valve and match all porting to the barrel or purchase a drop in valve.

I also highly recommend an SSG or short stiff spring. I think these are the key to these numbers.

If those 2 things are not done, you most likely will be disappointed. Check out the stock porting numbers under regulation.

shorty · « **Reply #38 on:** October 31, 2016, 10:58:31 PM »

Thanks Bob. Fat finger all fixed

Ozarkairgunner · « **Reply #39 on:** October 31, 2016, 11:48:18 PM »

That's pretty interesting how that small of a difference in port size can make that big of a difference. And also no I don't plan on boring it out either. That requires to much detailed work for the tools I have available, also I have not modified anything on my rifle yet, everything is still completely stock other than the SSG built in now, and I did it in a way so that all original components could stay in place without damaging anything, if I ever wanted to strip it back down and put it back to stock it'd be a simple process. What graphing charts do y'all use so I can try and get them too

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Calling all 25 cal marauder REGULATED guns

Author Topic: Calling all 25 cal marauder REGULATED guns (Read 52713 times - 1 votes) )

Author Topic: Calling all 25 cal marauder REGULATED guns (Read 52713 times - 1 votes)
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