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Gary Hindman's Custom Model 113 and Model 114

Both guns are bulk fill. They have a silver finish on the barrel and the CO2 tube. Stocks have been redone to a natural finish. Simmons .22 3x9x32 AO silver scope and rings are connected using IA mounts

Model 113- Predator Polymags .177- 5-shot groups @ 25 yds. =.440" C-C - Avg. velocity 697 fps 25 shots ( high 721 fps)

Model 114 - JSB Exacts .22 - 5-shot groups @ 25yds. = .54O" C-C- Avg.velocity 654 fps. 25 shots (high 660 fps)



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Steve. As requested. Here are the piston parts for the testing.

March 10 2012 at 9:54 PM
Phil  (Login Duane30)
Crosman Forum Member
from IP address 74.140.196.166

Here is the piston unit for testing. Mind you, this is a crude way of getting things to work. Not particularly taking a fancy to shaking the gun each end every time to get the piston out. Tried string, but is was getting hung up in the moving parts:
[linked image]

This is the piston seal with the cavity shown. The cavity volume is right at .0007cu.in./.011cc:
[linked image]

The next picture is the valve, again. This particular valve, though the same valve, has been altered at the piston side. If you can see it, there is a pronounced taper to match that of the conical shape inside the piston seal. There is a shelf the same with of the thickness around the edge of the piston to allow sealing contact:
[linked image]

The idea of tapering the valve face was to minimize losses between the o-rig and seal. Then, a well had to be created in the piston seal to allow clearance for the exhaust stem to pop and to act as air storage space. In addition, the well creates a more pliable piston seal wall.



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