First gun shoots sort of but not really.

[Bipedal]

I built a pneumatic cannon, and it works okay on paper. Sort of. I use a 1" JTV-100 RainBird valve, a 2' long 2" pressure tank, and a 2' long 1.5" breech loading barrel. It's not got leaks, but when I fire it at like 70 psi it's not very impressive. Stuff just sort of poofs out the end and falls flat. (I haven't modded the valve yet so it also honks and doesn't release as much air at once as it probably could.) Is my c:b ratio going to be really bad? None of my local hardware stores had pressure rated 3" pipes, I would have used that for the chamber.

[Slugfoot]

I believe that if your valve is honking then it should be fitted with a larger size pilot valve or the pilot you are using is not opening fast enough.....what are you using to pilot it?

[Bipedal]

Standard solenoid that came with it. I've got a blowgun and the connectors I need, I just need to buy some method of tapping a hole, some epoxy, and some hose and clamps. Anyone have pictures of modding theirs?

[Slugfoot]

There is a full tutorial in in a sticky in the "how to" database on this site. You should find that very useful. Good luck. Let us know how you get on.

[Bipedal]

Excellent. Thanks.