My dad built this cannon from scratch, wood, barrel, and wheels all made by him. The barrel is about 26" long and the bore is 13/4", just big enough to fire golf ball sized projectiles. We made up this blank charge (one ounce of fffg black powder with about 6 inches of packed paper wadding) just so we could make a big boom for Independence day. I think we accomplished just that, don't you?

We'll be working up an actual projectile charge eventually, and of course we'll post up the resulting video.