my 30 caliber p17 pcp ( version 2 build

[Rob M]

I was pursuing 2 even shots with the 20 ccs  or so on board.. been a lot of work , and have cuts all over my hands to prove it. I have one upper with 30 cal , another with 177 factory , and another with 25 cal 7 incher.. I use all 3 but went for peak fpe today.. Only did 13.4 fpe , but ill break 15 soon after some fine tuning like adding a 90 duro oring in the top of the valve.. The gun has severe limitations for tuning , and ill explain why,

20200112_091607 by murphyrobert9, on Flickr

20200112_091405 by murphyrobert9, on Flickr

Some of the challenges , like like a crosman or any other airgun is the porting.. But this is unique.. The top transfer port that butts up the barrel , it has a very small transfer hole of about .090 .. Well behind that internally is the actual sealing oring , so porting that is asking for real trouble.. It does seal after being opened up , but the oring ( 006_) gradually extrudes into the TP and the hole is literally where the oring is supposed to rest.

   The relationship from the valve itself to the hammer is also a constraint .. The hammer , to quote wyoman is really "sprung like a mouse trap.". This is due in part to the compressive seating force inside the valve.. In order to unseat the crushing force on the 006 oring you need a violent hammer.. The throw of the hammer is also short.. I have explored adjusting the nut placement on the valve stem , and this work seems promising as I recently detuned one gun to a fart.. But the cliff is steep and comes on fast. ( goes from fart to hand cannon in one turn ) The gun shoots best in 22 at 11 fpe.. and pretty well in 177 at 652 fps with standard 7.9/s..But the recoil of 30 cal is fun !


20200112_194408 by murphyrobert9, on Flickr
   Anyway , its been fun .. as of now the gun is perfectly sealed , barreled for 30 cal and fun to shoot.

[ranchibi]

Rob, that is pushing the envelope for sure! With your abilities you should be working with a different platform..you would work wonders! Very nice work on your P17! I recently picked one up and really enjoy it...but it’s nothing like yours!

[Rob M]

Thanks Randall , I do actually build a wide variety of guns( mostly oddball)  , but these were cheap and I really wanted to learn the inner workings..

[Back_Roads]

 Time and effort well spent IMO so many of these guns out there now so now there is some ideas what can be done if one can not resist to tinker.

[Rob in NC]

Love the oddball stuff.... great work!

[Rob M]

Love the oddball stuff.... great work!

thanks Rob.. I basically terrorize walmart bb guns (-'

[moorepower]

Well that is something you don't see every day!

[Rob M]

Well that is something you don't see every day!

lol, i think i have the only 2 p17 pcps in the world (-'