Long, long ago, in a land far, far away, our pistol club used a small public experiment to demonstrate ammo safety to the nervous and concerned. We took a liquor box, hung a .38 Special wadcutter round in it over a candle and closed the lid. Eventually, you got a muffled pop. Inevitably, there was unburned powder and the bullet never did more than make a dent in the cardboard. (Oddly enough, one time a primer did, sorta, almost. You could see it sticking out of the outside of the box.)
Modern propellant is incredibly hard to make to work properly, believe it or not. You not only need heat to ignite it, but you also need to contain it under pressure while it burns (normally in a disposable-cylinder, internal combustion engine made by S&W, Colt, Ruger, CZ, etc). Without both pressure and the heat, it just burns and not even that reliably. The movie scenes with small arms ammo being thrown into a fire and bullets whining off at high velocity in all directions are much like their depictions of explosions - not at all realistic.
It's theoretically possible for a cartridge in that scenario to go off. Theoretically. If it did, the bullet would certainly not be moving at normal velocity and the odds of an atomic-type chain reaction are essentially zip-diddly. Remember that most manufacturers sell bulk .22LR in loose boxes. They wouldn't do that if there was a real issue.
Modern propellant is incredibly hard to make to work properly, believe it or not. You not only need heat to ignite it, but you also need to contain it under pressure while it burns (normally in a disposable-cylinder, internal combustion engine made by S&W, Colt, Ruger, CZ, etc). Without both pressure and the heat, it just burns and not even that reliably. The movie scenes with small arms ammo being thrown into a fire and bullets whining off at high velocity in all directions are much like their depictions of explosions - not at all realistic.
It's theoretically possible for a cartridge in that scenario to go off. Theoretically. If it did, the bullet would certainly not be moving at normal velocity and the odds of an atomic-type chain reaction are essentially zip-diddly. Remember that most manufacturers sell bulk .22LR in loose boxes. They wouldn't do that if there was a real issue.
