Copper Marble Cannon

[liebls01]

I want to build a cannon out of copper parts that will shoot marbles and blowgun darts.
As I want to take it out in the field, to hunt rats on my farm and to scare the crap out of birds in the park, i decided i would pressurise it with a bike pump attached to the stock (like an old pump-up daisy).

Has anyone built one like this, if so, what did you use for the trigger valve. This is my biggest problem, i was going to use a blowgun trigger, but i keep hearing that they do not have good enough flow. However i wonder that matters so much at the low pressures i will be achieving with the bike pump.

Any answers or info/experience appreciated. I am in the middle of exams right now and need to finish this soon or i might be forced to study.

Thanks
Sam

[Aaron ?????]

my marble gun has a 1/2'' ball valve and that works fine at 100 psi wich is wat my gun usualy shoots at

another quality message by Aaron ????? inc.

[aussiecyclist]

i made a copper ccannon, and am using a sprinklerr valve. where the copper piping go's into the valve i have an adpter from the local plumbling shop that is threaded.

the layout is somthing like this

copper barrel -> at the end of the copper a threded joiner -> a PVC threaded joiner -> valve -> PVC threded joiner -> copper threded joiner -> copper piping

i have to silver solder the copper to the copper threading joiner

a bit confusing but i hope it helps