So yesterday I bump into an acquaintance of mine in town and, neither of us having anything else to do, repair to his ranch to check out his gun collection - great!
He opened his huge safe and we began to play with many of his toys - way too numerous to mention here.
We got around to the bottom shelf and the long guns, he pulled out an AR, removed the magazine and was about to open the bolt when either the rifle fired OR he accidentally fired the rifle into the back of the safe door.
Good Things: It was wearing a suppressor at the time so I still have some hearing.
The bullet entered the inside of the door at about 6" above the locking mechanism, all there was to show was a small hole in the material, nothing on the outside of the safe at all, of course. I'm not sure what brand the safe was but I'll report back when i next speak to him.
Had the safe door been closed he would, in a 'best case' scenario have been out several thousands of dollars for replacing 2 custom triple glazed windows - given the assumed trajectory

Bad Thing;
I was standing a little in front of him and about 18" to his right.......makes ya think?
Please be careful.