My first two shots didn't register and I had a double feed I deleted from the string. I'm impressed by the shot count. It looks like the regulator is around 1600 PSI
FX 34 grain
FX 34 grain
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My new P35
- Thread starter JimD
- Start date
For the P15 platform, if your goal is >40fpe, and you have already optimized porting to 75-80% of caliber, the plenum extension is a great idea.
Unless you optimize the porting, the plenum extension is not going to be as noticeable of an improvement.
For <40fpe, IMO the plenum extension is unnecessary. Optimize the porting first. In most cases this means simply increasing the barrel port to 75-80% of caliber. Some of these guns are restricted at the valve exhaust as well.
The P15 platform works very well when tuned in the .5cc-.75cc of plenum per fpe range
Unless you optimize the porting, the plenum extension is not going to be as noticeable of an improvement.
For <40fpe, IMO the plenum extension is unnecessary. Optimize the porting first. In most cases this means simply increasing the barrel port to 75-80% of caliber. Some of these guns are restricted at the valve exhaust as well.
The P15 platform works very well when tuned in the .5cc-.75cc of plenum per fpe range
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From the start I used a DonnyFL adapter and Tatsu. A member asked me how loud it is in stock form, so I shot it today without it. It wasn’t that bad, and it shot better without the moderator.
I ordered some hair curlers and felt to make some baffles.
I ordered some hair curlers and felt to make some baffles.
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Florida_Man,
You might want to ask Subscriber for 3d printed moderator design for your Bullshark. I'm using one in mackeral5's old .25 P15 and one in a .22 Diana Skyhawk. They work well.
You might want to ask Subscriber for 3d printed moderator design for your Bullshark. I'm using one in mackeral5's old .25 P15 and one in a .22 Diana Skyhawk. They work well.
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I might do that. I’ll see how the curler and felt works out. To be honest, the kids yelling in the pool at my neighbors house and the other neighbors hunting dogs barking at the kids was louder than the rifle in stock form. I was shooting into a cardboard box filled with clothes, so no impact noise.
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I measured about 85 db from a pellet hitting my trap. I tried clothes instead of rubber mulch and the noise from the trap did not change. But 85 db is OK, I get no complaints. My guns are now around 85 db using in shroud moderators designed by subscriber. I used to use curlers and felt and it was about equally quiet but the baffles or sometimes the curler would get in the pellet path and I'd get clipping. It might have been because the shroud slid forward. There is only one grub screw securing it. I think another member added another.
I looked at my data from my early days with my P35. My maximum fps with the 34 grain JSBs was 740 fps (that was peak, not average). That was before I turned the regulator down but also before I took a burr out of the barrel port. I got about another 30 fps on the FTTs it likes when I took the burr out. That is consistent with makeral5's comment about the barrel port being restricting. It would be pretty easy to increase it's size a little. I've already ordered a new barrel for my P35-25 so no real reason not to try it. I would start with a small change and test to see the impact. I was thinking of waiting for the new barrel to mess with this gun but it is very slow to arrive and this could be a reason to start with the old barrel. It isn't terrible but the P35-22 barrel has spoiled me. I'd be happy with 820 fps with 34 grain JSBs which doesn't seem unreachable. My P35-22 is very accurate at 835 with 21 grain H&Ns. Trajectory is reasonable even though it isn't as fast as some want.
I think my path is to get a baseline fps with FTTs and 34 grain JSBs, maybe 25.4 grain too. Since that is temperature dependent I will try and get the before and after at about the same ambient temperature. Then put in the plenum and measure velocity again. If it isn't >800 on the 34 grain, try a small increase in the barrel port. I haven't opened the regulator end of my P35s yet but I haven't needed to. I've turned the reg down 1/4 turn so I can easily turn it back to the as received level. I'm hoping not to have to go much higher than that. Decreasing the regulator increased my shot count about 10 to about 70 shots per fill. It would be nice to get the added power without going down too much on shot count. If I change the regulator I'll retune the hammer spring but I guess I may need to do that after the plenum installation to. I set the hammer spring in my P35s at about the hammer spring setting that gives me maximum velocity. I've tried lower but then my first shot velocity is lower than the rest of the string.
I looked at my data from my early days with my P35. My maximum fps with the 34 grain JSBs was 740 fps (that was peak, not average). That was before I turned the regulator down but also before I took a burr out of the barrel port. I got about another 30 fps on the FTTs it likes when I took the burr out. That is consistent with makeral5's comment about the barrel port being restricting. It would be pretty easy to increase it's size a little. I've already ordered a new barrel for my P35-25 so no real reason not to try it. I would start with a small change and test to see the impact. I was thinking of waiting for the new barrel to mess with this gun but it is very slow to arrive and this could be a reason to start with the old barrel. It isn't terrible but the P35-22 barrel has spoiled me. I'd be happy with 820 fps with 34 grain JSBs which doesn't seem unreachable. My P35-22 is very accurate at 835 with 21 grain H&Ns. Trajectory is reasonable even though it isn't as fast as some want.
I think my path is to get a baseline fps with FTTs and 34 grain JSBs, maybe 25.4 grain too. Since that is temperature dependent I will try and get the before and after at about the same ambient temperature. Then put in the plenum and measure velocity again. If it isn't >800 on the 34 grain, try a small increase in the barrel port. I haven't opened the regulator end of my P35s yet but I haven't needed to. I've turned the reg down 1/4 turn so I can easily turn it back to the as received level. I'm hoping not to have to go much higher than that. Decreasing the regulator increased my shot count about 10 to about 70 shots per fill. It would be nice to get the added power without going down too much on shot count. If I change the regulator I'll retune the hammer spring but I guess I may need to do that after the plenum installation to. I set the hammer spring in my P35s at about the hammer spring setting that gives me maximum velocity. I've tried lower but then my first shot velocity is lower than the rest of the string.
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Can you tell me more about this Subscriber in shroud moderator and does someone sell them or do you have to 3D print them yourself. I cant seem to find enough information on it and I also cannot 3D print. I'm a new acquirer of the XM-1 bullpup .22 and would like to quiet down the gun as much as possible for some back yard pesting as well as learning about any other mods that can be worth doing for more consistency. I've heard of the haircurler mod you can do to it but if there's a better solution I'm all ears. I plan to change out the baffles and throw on a Weihrauch moderator on it. I find Weihrauch moderators extremely excellent for sound dampening while remaining very lightweight.
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I took the baffles out of my Bullshark and did the hair curler mod. I'm also running a 3d printed suppressor that's the same diameter as the shroud and it's the quietest pcp I own.
Subscriber is a member here. You can search for him by name using the member search function. I know he designed the internal baffles, but I don't think he prints them.
Subscriber is a member here. You can search for him by name using the member search function. I know he designed the internal baffles, but I don't think he prints them.
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Can you explain your process of the hair curler mod as well as the products you used for it, I know the P35 and the Bullshark have slightly different baffles and shroud lengths.
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The mod is easy. You just need to cut one of the curlers to length to fit inside your shroud. Here's the video that explains it.
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I may do a longer separate thread but I've been messing with my P35-25. I first tuned it back up to about where it came to me for about 710 fps on the 33.95 grain JSBs. That is an average for 8 shots. Then I tried drilling out the barrel port. A 3/16ths drill bit was the biggest that would go into the port. I think that is about 75% of the .25 barrel diameter. I used a #3 drill bit, a bit bigger than a 7/64ths to make the barrel port about 85% of the barrel diameter. No change in velocity. Then I drilled out the transfer port and the passage way through the aluminum block everything mounts into. They were all about 3/16 diameter. On the heavies (33.95) that gave me about another 20 fps. I am not sad I did it but I don't know if that's worth the effort. It's not terribly difficult but you have to spend time getting all the metal chips out of the gun. Next I installed the South African power plenum and that made a very noticable difference. 33.95 are going about 775 fps on average. So a gain of nearly 50 fps. This is in 60 degree weather so they would be going faster in the summer. I got 945 fps on the light FTTs (and they are inaccurate at this speed), 872 fps on FX 25.4s, and 813 on 31 grain Baracudas. I sighted the gun roughly (it's windy) at 30 yards with the FX today. The Baracudas seem more accurate and only a little below and right of the FX. I shot some groups with the 33.95 as I was checking velocity and got some under 1/4 inch groups (3 shot) at 25 yards with the 33.95 grain JSBs. I do not have many left so I did not shoot groups today in the wind with the 33.95 grain. This barrel is looking better at the current tune. My 30 yard 3 shot group with the Barracudas was about 3/8ths despite the wind (2 in one hole).
I also messed with increasing the regulator setting. But I do not have hammer spring enough to use a higher regulator setting. That could be deliberate to save the poppet, I do not know. My 25 has a .117 shim under the hammer spring. I drilled out a #10 washer which is .04 thick and added that to try and increase hammer spring force. I had to turn the hammer spring down over 1/4 turn to be able to cock the gun. The pitch on the hammer adjuster is 1mm so my net increase in spring force was only .02 to .03 inches compression on the spring. I turned the regulator up but velocity did not increase, not enough hammer I think. I think it will require a new hammer spring to get any more velocity. That might not work well with the stock poppet. Or it might work great and get me up to 50 fpe (about 45 fpe now). I think the limited hammer spring force is the limitation on power, not so much the passageways.
I saw one spring that might work on McMaster Carr but I will probably stop messing with it for now. 45 fpe isn't bad. It shoots through 3/4 plywood at 25 yards now with the FTTs or the JSB heavies. The trajectory of the 33.95s would be better if I could move them 100 fps faster but that doesn't seem realistic. Even 50 fps more would get me over 50 fpe, however, and improve the trajectory. I think if I change the hammer spring I need to know where I would get a replacement poppet if I ruin mine messing around. I also want to understand where I am in shot count, at least roughly. I keep draining my 45 minute tank filling an empty gun and can't fully charge the gun at the moment. But 20 minutes or so with the YH will fill the tank (again).
Florida_man, if you put your plenum extension on you may need to find a different O-ring for where the body of the extension joins the back piece from the current air cylinder. The one they supply did not work. I think the one I got to seal was a 20mm 2mm thick. I had to stretch it out some but it sealed well. If you can see the O-ring with the pieces threaded together it will not withstand pressure. Threads were also a little stiff on that junction, not difficult with a wrench but stiff with just my hand. Other end threaded well. My other tip is if you change the reg after installing the extension you will need to do it from the back, I think. I couldn't loosen the lock nut from the gauge end. The O-rings will lock things up with more use but right now, I had to pull the reg out of the gun to change it. It's easier to make the change that way but a little more work to remove it.
Any time you open the air tube (for a reg change, for instance) YOU HAVE TO DEGASS FIRST. I made mistakes but not this one. If you unthread one of the nuts on the air tube with it pressurized it will become a projectile, however. Somebody could get hurt. An indication you did not get the air out is if things are difficult to unscrew by hand. If you need a wrench, you need to double check the pressure. Sorry for the lawyer paragraph but I don't want anybody to duplicate these steps without remembering to degass.
I also messed with increasing the regulator setting. But I do not have hammer spring enough to use a higher regulator setting. That could be deliberate to save the poppet, I do not know. My 25 has a .117 shim under the hammer spring. I drilled out a #10 washer which is .04 thick and added that to try and increase hammer spring force. I had to turn the hammer spring down over 1/4 turn to be able to cock the gun. The pitch on the hammer adjuster is 1mm so my net increase in spring force was only .02 to .03 inches compression on the spring. I turned the regulator up but velocity did not increase, not enough hammer I think. I think it will require a new hammer spring to get any more velocity. That might not work well with the stock poppet. Or it might work great and get me up to 50 fpe (about 45 fpe now). I think the limited hammer spring force is the limitation on power, not so much the passageways.
I saw one spring that might work on McMaster Carr but I will probably stop messing with it for now. 45 fpe isn't bad. It shoots through 3/4 plywood at 25 yards now with the FTTs or the JSB heavies. The trajectory of the 33.95s would be better if I could move them 100 fps faster but that doesn't seem realistic. Even 50 fps more would get me over 50 fpe, however, and improve the trajectory. I think if I change the hammer spring I need to know where I would get a replacement poppet if I ruin mine messing around. I also want to understand where I am in shot count, at least roughly. I keep draining my 45 minute tank filling an empty gun and can't fully charge the gun at the moment. But 20 minutes or so with the YH will fill the tank (again).
Florida_man, if you put your plenum extension on you may need to find a different O-ring for where the body of the extension joins the back piece from the current air cylinder. The one they supply did not work. I think the one I got to seal was a 20mm 2mm thick. I had to stretch it out some but it sealed well. If you can see the O-ring with the pieces threaded together it will not withstand pressure. Threads were also a little stiff on that junction, not difficult with a wrench but stiff with just my hand. Other end threaded well. My other tip is if you change the reg after installing the extension you will need to do it from the back, I think. I couldn't loosen the lock nut from the gauge end. The O-rings will lock things up with more use but right now, I had to pull the reg out of the gun to change it. It's easier to make the change that way but a little more work to remove it.
Any time you open the air tube (for a reg change, for instance) YOU HAVE TO DEGASS FIRST. I made mistakes but not this one. If you unthread one of the nuts on the air tube with it pressurized it will become a projectile, however. Somebody could get hurt. An indication you did not get the air out is if things are difficult to unscrew by hand. If you need a wrench, you need to double check the pressure. Sorry for the lawyer paragraph but I don't want anybody to duplicate these steps without remembering to degass.
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@JimD
Thanks for the info! I have one of these poppets I planned on installing when I finally open this thing up. I’ll have to verify the length, possibly trim it down.
Thanks for the info! I have one of these poppets I planned on installing when I finally open this thing up. I’ll have to verify the length, possibly trim it down.
Smk Diana skyhawk snowpeak Onix Artemis P15 P35 longer heavy duty exhaust valve | eBay
Smk P15 P35 Diana skyhawk Spa Artemis Onix exhaust valve fits all caliber's. when in the valve body.
www.ebay.com
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Nice to know they are available but not inexpensively when you factor in the shipping. But an option. Thanks.
Looks like Bagnall and Kirkwood have OEM exhaust valves for less. Wonder what is "heavy duty" about the ebay one.
Looks like Bagnall and Kirkwood have OEM exhaust valves for less. Wonder what is "heavy duty" about the ebay one.
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I’ll photograph them side by side. I don’t know if it’s just because it’s stainless steel “air craft grade” haha
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I just sent an email to extreme airguns asking if they sell hammer springs and their thoughts on whether the P35 poppet will survive a stiffer spring and regulator increase. I think they have made some higher powered guns from the videos I've seen posted so I am hoping for useful comments. I will let you know if I get something back.
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Kleezy, all three of my P35s have 3D printed moderators inside the shroud. They are about 120mm long so I had to slide the shroud forward for about an inch and a half for them to fit. The designs are different in the 3 guns but they seem to have similar effect on the sound. I measured about 85db about a foot in front of the muzzle and a meter to the side with the 22 and 25 (before the recent power increase) and a little less for the 177. All the moderators were made for a 22 caliber so I had to drill one out a bit for the 25. "Subscriber" designed the moderators and referenced me to another member who 3D printed them. I paid the guy who printed them a small fee approximating his cost of the materials he used. If you want one and subscriber is unresponsive I will try to find information on who printed them.
My hope that the velocity increase helped this barrel were disproven this morning. The wind calmed down so I put a 8-32 scope on my P35-25 and tested 31 grain Baracudas, 33.95 grain MK1 and 33.95 MK2 at 30 yards. I shot a 5 shot group with the Baracudas first and it was about .7 inches center to center. Next was the MK1s and I quit after three shots, they were over an inch and a quarter apart. The MK2s were last. I'm pretty sure I pulled one but I shot a total of 6. If I count the one I think I pulled the group is about an inch center to center. If I ignore it, the 5 shot group is about .65 center to center. These group sizes are what this barrel has given me previously at lower power level. I can't tell if it likes Baracudas or MK2s best but I won't stock up on pellets until Krale ships me the new barrel I ordered from them in April. It might have a different preference and will hopefully be more like Florida_man's.
I got a response from Extreme Airguns this morning but no answers yet (he wanted to know more about my gun and what I've done to it).
The plenum increases the length of the airtube but the moderators I'm using require the shroud to shift forward almost the same amount. I put a stock baffle in my shroud to make it the same length as the airtube with the plenum extension. The gun is maybe half an inch longer than it was. I'm happy with that.
My hope that the velocity increase helped this barrel were disproven this morning. The wind calmed down so I put a 8-32 scope on my P35-25 and tested 31 grain Baracudas, 33.95 grain MK1 and 33.95 MK2 at 30 yards. I shot a 5 shot group with the Baracudas first and it was about .7 inches center to center. Next was the MK1s and I quit after three shots, they were over an inch and a quarter apart. The MK2s were last. I'm pretty sure I pulled one but I shot a total of 6. If I count the one I think I pulled the group is about an inch center to center. If I ignore it, the 5 shot group is about .65 center to center. These group sizes are what this barrel has given me previously at lower power level. I can't tell if it likes Baracudas or MK2s best but I won't stock up on pellets until Krale ships me the new barrel I ordered from them in April. It might have a different preference and will hopefully be more like Florida_man's.
I got a response from Extreme Airguns this morning but no answers yet (he wanted to know more about my gun and what I've done to it).
The plenum increases the length of the airtube but the moderators I'm using require the shroud to shift forward almost the same amount. I put a stock baffle in my shroud to make it the same length as the airtube with the plenum extension. The gun is maybe half an inch longer than it was. I'm happy with that.
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