Tuning Sharing a little Crosman love ... Bastard P-rodish custom w/ bottle

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Motorhead

Motorhead

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Nov 1, 2018
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California, United States
Lol ... Making guns from piles of parts !!

Starting with an old P-rod receiver & cocking bolt .... Added and machined a 19" crosman .22 barrel for the breech o-ring .... Add an old 1701 shorty air tube .... use a crosman valve drilled to transfer exit at @ .125", transfer port & barrel ... Steel end cap with Steel 90* fitting into an On/Off ASA manifold .... Ninja Reg at @ 1400 psi with a prototype SHORT bottle of @ 7 cu in or so. Grippy taped it becomes the forestock. Made an SSG devise to go along with an MDS/Brass core hammer.
Assembled the entire 1701 tube becomes the Plenum, bottle ends right before gauge so we can read plenum pressure and a big gauge at the reg. * as you can see, guns plenum is empty, yet bottle in near full
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Made a full length shroud to fit factory mount, stripper and end cap. set it up to shoot a 14.3 Crosman pellet at @ 800 fps ... pretty dang quiet too. Crosman Butt stock we have a semi-mini carbine that weights 5 1/2 pounds with the 4x scope !!!

Are we having fun yet ? ... YES WE ARE !!!



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Scott S
 
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Now THAT is creative!!! Respectable velocity too for a P-Rod!

I've had one since 2013-2014, but I have yet to clean the barrel or service it! The only time I went in there was years ago when I tossed a Hill de-pinger in there lol. Told myself that I'd leave it alone until it spring a leak, but these things are apparently leak-free AFAICT! 😂 

I would like to make a tank doubler for it, but this gives me some ideas Scott!

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Fiddled a bit more yesterday on the Hammer and SSG. The cocking effort was IMO too dang stiff for the 20 fpe output. Had installed an @ 26 gram MDS nylon / brass core hammer with a smaller diameter spring similar to OEM & coupled to an SSG.

Out came the hammer and another went in of the same 2 part type construction tho weighting @ 38 grams. Changed out the spring to one of larger O.D. also modifying the rear cap to accept it. Reconfigured the SSG spending a bit of time getting the spring rate correct so as NOT TOO over dwell the valve. That done we're back at @ 805 fps velocity and cocking is much softer and smoother.

Simple physics ... heavier hammer requires less spring energy. In all my R&D with light hammers, the hammer Stroke of these pistols is Short so to get sufficient energy transfer need to run more weight.

Scott
 
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@ 2 months now and not shot it much. As sun was about to set grabbed a tin of Crosman CPHP 14.3's, Aired up to 3000 # and took a evening walk to just go plink.
Intent here was see HOW MANY SHOTS we get on a fill shooting from 3K to reg set point of 1.4K
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Well it turns out to be 53 full power shots at 800 fps.
Not too bad for such a small HPA tank. More than enough for a light weight pistol carbine taken camping or just out for a walk.

Scott S
 
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