This is just a test barrel and breech block that i made from some scrap. I'm thinking something like this would make a nice French 75 firecracker cannon. With the barrel clamped in a vise and taken outside for testing, everything worked great. The charge was 10grains of FFFG GOEX, and the projectiles were firecrackers. The only thing that holds the breech in place is the side bolt handle. It's simple and easy to make, but is it safe?