Does This Sound Like A Good Plan?

[Satasaurus]

Never mind

Mods please delete

[Solar]

Using the pvc glue usually prevents re-use of the parts later, even if threaded. Maybe teflon tape would give you a good seal and still be removeable. I would say to glue your chamber together and have a threaded hole on one end. Then just make a different size chamber if you want later. pvc is inexpensive enough.

[Solar]

You can find a reducer to get the end cap threads down to 1/8" NPT thread size. Order a tire valve that has that thread size to use. You can use a T fitting to put a safety valve onto it as well. You can find safety relief valves at hardware stores that open around 100 or 150 psi. Most tire pumps can only produce about 90psi so you should be ok, but one is always good to have.

[Satasaurus]

Never mind

[cammyd32]

Ball valves are usually quite stiff when you first get them, they will ease with use, but also if you put some oil on them they will open a treat.

[mattyzip77]

I always use threadded fittings for my cannons so I can make them into other cannons later or use a different barrel on a cannon, etc..

[Satasaurus]

Never mind