its about 1" diameter by 24" inches long, and its got excess from a handle and elbows.. So its a bit bigger..

I might go for this,

How long do you think this would last if i use about 100-200psi for each shot with my gun?

Well i made pneumatic gun out of steel and metal and for the valve i have a plastic sprinker valve which is electronically hooked up to a door bell ringer as a trigger. I fill the pressure using a bike pump but i wanted to use something else cause a bike pump can make you tired.. I am looking for a ...

How do you keep the potato or ammo from rolling down into the combustion chamber?