When I was a teen, we were out camping and one evening a buddy threw a .22 into the campfire. We all ducked for cover and waited. Nothing. My buddy goes over and says, "It landed in the ashes" and proceeded to nudge it towards the fire with his finger. Naturally it goes off and he grabs his hand and yells. The brass case was torn open and lodged in his finger. We had to use a fork to pry it out. He didn't do that again.
[Sidebar] I remember seeing a Hopalong Cassidy movie where he sneaks up on a bunch of rustlers and lobs a bag of cartridges into their campfire. The rounds start popping off and the bad guys are dropping like flies. That and the 50-shot six-shooters were my favorites. Only in Hollywood.