Two True Stories,
Several decades ago the Log Cabin Store in Lodi Ohio displayed a cap and ball cylinder that was blown apart. The attached story: Two friends borrowed this revolver and loaded it with ball,,, and powder collected from firecrackers. The first time they fired it the cylinder showed a crack. In a "oh ****, now what" moment they found that a discarded pistol centerfire case was a near perfect fit in the cracked chamber. They took the revolver home and clamped the cylinder in a vice to solder the repair in place....without unloading the rest of the chambers.
Closer to home, I have had since middle school a homemade cannon that would put a marble thru an oil drum. I usually loaded it with a thimble full of black powder and a sheet of packed Kleenex. Made a glorious boom and mess of shredded paper. It has a very small touch hole. I used to be able to buy fuse that was a very fine copper wire coated with sparkler ??? chemicals. When that supply dried up I used fuses pulled out of firecrackers. The last time I played with my "toy" I used fuses from a pack of firecrackers that said "Warning, do not disassemble" which I ignored. The first half dozen fuses worked as expected. The next fuse burned very fast and fired the cannon before I could back away.