My cannon story.
I built a cannon once. I was working in Dallas and acquired an aircraft high-pressure air dryer for a pneumatic system. It was full of desiccant when I started. The dryer was about 2.25 inches in diameter and about 18 inches long. Thick walls and heavy screwed-on end pieces made it perfect for a small cannon. The green cannon fuse you find at gunshows fit the inlet port perfectly.
I didn't have a method of attaching it to a stand so we just propped it up on a stump to fire it.
The Test
We were camped out on the North side of Lake Grapevine near a little town called Flower Mound. In 1979 there were only about 3 or 4 hundred people living there. We had a good turn out for the camp-out. We usually had a 2 or 3 day keg party and some had their kids. Was always a good time.
In the late afternoon we cut a branch that was the approximately bore size and wrapped the wooden projectile with duct tape to ensure a proper fit. I inserted a 6-inch length of cannon fuse, poured a handfull of ffg black power and dropped the projectile into the bore. We found a suitable stump that allowed recoil support and pointed the cannon over the lake. I lit the fuse and we all left the area. There was a tremendous BOOM. Lots of smoke. Grass was flattened in a 30-foot arc by the shock wave and the wooden projectile went out of sight over the lake. The cannon was still intact. Hey, we can do this again!
We shot it a few more times that evening. The kids got nearly as big a kick out of it as the adults. I knew that I had a good thing and was thinking of a way to make a portable stand and make this a weekly event.
The Police
After the sun went down, we thought, I wonder what it would look like at night? So, we get it ready, light it off. BOOM, 4 Patrol cars with the local Flower Mound police telling everyone to get their hands up. Scared the kids to death. Anyway, we were nice, the kids helped. The police took my cannon because it was threaded on both ends. I offered to cut one end off, but they said that if I wanted to sign a receipt I could try to pick it up the next day. I declined. Sure was a lot of fun.