The Punisher

[Torch]

Its a diaphram valve. You pump it form the back and it seals on the barrel inside filling the chamber around the barrel. Just like a sprinkler valve works. but a disk of rubber would seal better methinks.

[Viper]

excellent piston gun Me and my uncle are planning to build my first pneumatic this weekend. It will have interchangeable barrels to accomodate different types of ammo. ie. marbles, paintballs, tennis balls, potatoes, screws, you get the point.