SpudFiles

Hey guys,

I recently got a free .22 cal. pellet gun barrel that came off a QB78 for free. so i needed a place for it to go so i have been playing around with paint and came up with a design but im not sure if it will work due to the amount of leaks that could occur. Basically there is a bolt (pink) that brings back a cocker (blue) and releases to hit the hammer valve, but how do i reduce the amount of leaks from the hammer valve into the bolt because i cant seem to find out a way to put an o-ring in between the too that wont shred when moving the bolt

This is how Crosman does it.

i have seen this picture on air gun artisans before maybe you can help me out here why would they have a) the stem on the valve so long b) y would u have what looks like a piercer on the end of the stem? wouldn't the cartridge already be pierced?

if u look at a 12 gram it is sealed u need somthin to peirce it

Pocket, you were worried about leaks, right?

In the diagram I put up, you can see that the solution used by Crosman, is to put the transfer port DOWNSTREAM of the loading port.

The probe on the bolt pushes the ammo ahead of the transfer port, and an o-ring on the bolt seals things.

I couldn't tell you why Crosman engineers made the valve stem that long.

Maybe the diagram is not to true scale?

As to the piercing pin;

With the 2240, you load a fresh cartridge, work the bolt (which cocks the hammer), and pull the trigger.

This pierces the fresh cartridge allowing CO2 gas to fill the valve. Ready to shoot.