same thing you are i hope
i dont use any projectiles in this cannon...umm i am scared to!
i use a rammer to tamp down the load and then use aluminum foil as packing..i am a "baby" cannon student and am learning as i go...
i did also make a "bb cannon" its bore is .177 and fits a bb down the bore to a narrower breech..it is pretty cool..i call it a micro cannon...not my idea..but it is cool....
the bolt cannon is .50 caliber...or near as its just over a 1/2" bore.
it does not have a "breech"

...the vent is 1/8"....
my bb cannon malfunction by blowing out the vent..i think the vent is too high on the breech(not at the bottom)....
i think the actuall manufacturing of the cannon is the best part...the bang aint bad neither
