Picked up a plenum for my Bullshark and got the chance to install it this morning. Supper easy install but had to apply a little heat to reg to get it loose. I'll be testing it out this afternoon to see what kinda difference it makes.
Snowpeak XM1 Bullshark plenum install
- Thread starter Neu
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Following this one. I'm getting 25 fpe with .177 13.43 Knockouts and 2 turns on the hammer spring. I'm pretty happy with that, but I'm still interested in seeing what you get.
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Me too. If I get a good barrel on my 25 caliber I may try to set it up for ~50 fpe and I think a larger plenum may be required.
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So I was chasing a leak all afternoon with the plenum got that figured out then the fill prop o-ring decided to leak lol. Anyways just did a quick Chrono ( it's dark now) with some 23.14 grain pellets. 5 shots were 860-863 for around 38fpe. I did turn the reg down a smidge when I had it apart so....
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Finally got to test it some today, initially was not to impressed didn't seem to make much of a difference in power or shot count. Thought about it and thought to myself maybe the reg pressure is to high for the hammer spring.... Took it apart got the reg down to 125 bar. Now it's shooting 18.67 grain at 895-905 fps (seems to be the spot this rifle likes) with a little under 2 turns on the hammer. From 248 bar down to 125 bar I got 85 shots on the regulator. I am pretty sure I'm going to leave it there, I was getting a little under 1/2 in groups at 48 yards.
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I have over 4000 34 grain pellets, and another 1000 25 grain. From what I read the plenum might help with those 34’s. I sold my only 25 cal, so the pellets have just been sitting on the workbench
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For anyone that might be interested, Lane has P15/P35/Bullshark plenums now. I have one coming for my .177 Bullshark. I'm not seeing any gain in velocity past 1.5 turns on my hammer spring, so I'm hoping that having more volume available will help.
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The South African plenum gave me about 40 fps more on my P35-25 as I posted in another thread yesterday. I got about 20 fps by drilling out the barrel port, transfer port, and the path through the block between them from about 75% of bore size to about 85%. That puts me at about 45 fpe. Getting 50fpe will require a heavier hammer spring. The one in my P35-177 was too much for the regulator setting it came with and I shortened it. But the 25 came shimmed a little and is too weak for higher regulator settings. Trying to decide now if I go further or not. The current tune has Baracudas (31 grain) going about 815 fps. The 33.95 grain JSBs are about 775 which isn't ideal but the trajectory Chairgun predicts for both is plenty usable. I need to figure out which is more accurate. I was shooting little 3 shot groups as I tested each change of the gun and both looked pretty good.
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My Bullshark reg seems to be set around 140 bar. If I'm not mistaken, you said yours was lower than that? Mine is going to be fed 10.03 and 13.43 slugs 99 percent of the time so speed is what I'm after.
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Ed,
The short answer is yes, I am sure the reg on my P35-177 is significantly lower than that, I estimate about 125. It's hard to judge because of what happens with these guns when you go under the reg. The velocity increases for about 10 shots and then starts to fall. I am confident the reg on my P35-22 and P35-25 are no higher than 150, I think they are about 140. I've tried turning up the reg on the P35-25 and the velocity drops because I don't have a stiff enough hammer spring to open the valve. I just shot another fairly long string with the 25 caliber this morning. I happened to look at the reg during this string when it was about 150. A few shots later the velocity started to increase but not a lot 2-6 MPS. It did not come back down to where the main string of 29 shots was for another 14 shots. If I calculate the bar/shot for the first 29 I get 2.5 bar/shot. For the last 14 I get 1.79 bar/shot. Seems like just another indication that I was off reg for the final 14. (you might also be interested in the fact this string was with Nielsen slugs - they shoot pretty well from my 25)
You may remember I shortened the hammer spring on my 177 to get it to stop shooting the first shot slower than the rest. It had too much hammer spring. My 25 caliber came with a spacer under the spring and still I run out of hammer spring around 140-150. I don't know if you have a different spring or what.
Jim
The short answer is yes, I am sure the reg on my P35-177 is significantly lower than that, I estimate about 125. It's hard to judge because of what happens with these guns when you go under the reg. The velocity increases for about 10 shots and then starts to fall. I am confident the reg on my P35-22 and P35-25 are no higher than 150, I think they are about 140. I've tried turning up the reg on the P35-25 and the velocity drops because I don't have a stiff enough hammer spring to open the valve. I just shot another fairly long string with the 25 caliber this morning. I happened to look at the reg during this string when it was about 150. A few shots later the velocity started to increase but not a lot 2-6 MPS. It did not come back down to where the main string of 29 shots was for another 14 shots. If I calculate the bar/shot for the first 29 I get 2.5 bar/shot. For the last 14 I get 1.79 bar/shot. Seems like just another indication that I was off reg for the final 14. (you might also be interested in the fact this string was with Nielsen slugs - they shoot pretty well from my 25)
You may remember I shortened the hammer spring on my 177 to get it to stop shooting the first shot slower than the rest. It had too much hammer spring. My 25 caliber came with a spacer under the spring and still I run out of hammer spring around 140-150. I don't know if you have a different spring or what.
Jim
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well there is Huma
huma-air.com
Snowpeak Artemis P35 Power Tune Regulator and XL Plenum By Huma-Air
Snowpeak Artemis P35 Power Tune Regulator and XL Plenum By Huma-Air
Huma-Air pressure regulator with XL plenum for tuning your Snowpeak - Artemis P35 for high power applications
huma-air.com Upvote 0
Thank you!
I did see that one as well, I suppose switching to the Huma reg would only certainly aid in shot to shot consistency. That might be more worth it.well there is Huma
Snowpeak Artemis P35 Power Tune Regulator and XL Plenum By Huma-Air
Snowpeak Artemis P35 Power Tune Regulator and XL Plenum By Huma-Air
Huma-Air pressure regulator with XL plenum for tuning your Snowpeak - Artemis P35 for high power applications
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The only drawback to the huma is it takes up air space in the cylinder. I just remembered my bullshark came with a Huma reg and plenum. I might try that in my P35 before fitting the SA plenum. Jim said the orings that came with his SA plenum didn’t work and he had to grab some from his supplies. I don’t have anything that appears to be the same size.
The notos and P35/Bullshark use the same regulator.
The notos and P35/Bullshark use the same regulator.
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It is summer time here, of course, and I got 795-815 fps every day for about a week. That is with JSB 33.95 MKIIs. Temperature from around 80 F to 94 F. I had it tuned as high early this year when the weather was cooler with a higher regulator setting. But in warm weather my velocity plummeted to under 600 fps. So I wanted to be sure this one works in warm weather. I had to turn the regulator down to get velocity back up around 800 fps. If velocity in the winter is only 775 I will be OK with that. I'm chasing a slow leak currently. I tried the cheap/easy route of just putting a little more silicone grease on the O-rings. Seems to still be leaking. I'll know better in the morning. I think it's lost 10 bar in 3 hours. If it continues to fall overnight I will take it back apart tomorrow and change the O-rings in both ends of the gun. Slow leaks are a PITA.
My comments earlier about how much I got from the plenum versus drilling it out were from memory and a little off. I looked at my notes and I only got about 10 fps from drilling the barrel port and path from the valve to the barrel port from 75% of bore diameter to 85%. I got about 50 fps from the power plenum. If I had to guess which O-ring is my slow leak it would be the one on the plenum but I still like that change for this gun. I'll like it even better if a new O-ring fixes it. It could be something else, of course. Usually I find the leak at the inlet end.
I have had zero issues with my SPA regulators. I often get a ES under 10 for a 20-40 shot string. I've never had to touch them. I had to do some work on the Huma in my Caiman X. It was much worse initially but now that it's fixed it works as well - but no better.
My comments earlier about how much I got from the plenum versus drilling it out were from memory and a little off. I looked at my notes and I only got about 10 fps from drilling the barrel port and path from the valve to the barrel port from 75% of bore diameter to 85%. I got about 50 fps from the power plenum. If I had to guess which O-ring is my slow leak it would be the one on the plenum but I still like that change for this gun. I'll like it even better if a new O-ring fixes it. It could be something else, of course. Usually I find the leak at the inlet end.
I have had zero issues with my SPA regulators. I often get a ES under 10 for a 20-40 shot string. I've never had to touch them. I had to do some work on the Huma in my Caiman X. It was much worse initially but now that it's fixed it works as well - but no better.
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