Barrel keys are one of those things we generally don't think much about but should pay some attention to. I just heard of a horrible accident from last season. It seems a fellow was bird hunting with a 12 gauge side by side muzzleloader which had a loose barrel key. He didn't have the ramrod under the barrel but used a length of 5/8" dowel thrust through his belt. He was carrying the gun over his shoulder, triggers upward as many of us do. The barrels fell off, came down with one cap striking a rock and he took the full charge in the butt. Lest any one laugh at the idea of a fellow shooting himself in the butt let me assure you it wasn't funny, he died a slow and agonizing death. Do make sure that barrel key is tight!