Whilst we're telling all these stories about old ammo without issue, I need to pass on one of another type from Charlie Petty. It seems there was an old coot who kept a box of .30-30 in his pickup for his truck gun for quite awhile. Well, after some time, he fired one and the rifle kinda disassembled itself.

When an independent lab broke down a couple remaining rounds (yes there was a lawsuit involved), it seems the long term vibration turned the powder into....well, flour or something similar. Burning rate was pretty much instantaneous. The ammo company was found without fault.

Moral of the story is apparently don't get cheap- it can be really expensive.