yeah it's from leftovers, not from a cannon leftovers, but plumbing leftovers
specs:
main valve: 3/4" ball valve.
barrel: 1/2" stainless steel (I think), about 20 cm long.
chamber: 1.5 diet coke bottle.
filling valve: a kind of a 1 way valve i found thats can screw on to the pump i use it's working great and no leaks for now ( despite of that i'm operating the thing on low pressure, can't get high with this pump....).
some pictures:


with some ammo i've made:

the valve crappy setup:

I know it seems bad but it doesnt leak









