1. Out spotlighting with friends with a recently purchased Savage 99 in .243Win, 5 rounds in the rotary mag. Saw a roo, cocked it muzzle up and as the lever reached the last 1/8" it went off, frightening the bejeezus out of all of us. The previous owner had filed the trigger sear down to the point where the rifle was totally unsafe to use.
2. Morning after a big shoot, cleaning the rifles outside on the patio; opened the bolt and the 22 Mag went off narrowly missing my brother and putting a hole in my mate's Holden Torana (car).
I was mortified, brother was pale and shaky, mate was livid.
I'd put the safety on the night before and pulled the trigger, nothing, so someone else got the bunny. I'd left the round in the breach and found out the hard way that the 'safety' had simply delayed the pin fall and it fell when I moved the bolt.
I have not trusted a safety since.
3. Friends had 12ga pumpaction shotgun in the ute (pickup) between the driver and passenger (butt on floor, muzzle up towards the back window). The passenger jumped in and somehow put his finger through the guard and let one off in the cab. Ringing ears for days and a big hole in the back window and cab surround.
4. I was driving the ute one night and as I got out for a smoke the shooter on the back closed the side by side 12ga on 2 shells and it went off. Put a hole in the steel tray, hit the sub-frame and glanced off, and if I'd been just a smidgen quicker I'd have copped a gutful of No4 shot. The pins of the faulty gun were still protruding when he closed it and they set it off.
5. Shooting rats with a shotgun and rat shot. A case failed to go off so mate decided to keep cocking it and firing as he walked back to the ute, he had the hammer shotgun pointing down in a safe direction but very low when it went off and the butt caught him a stunning blow in the goolies. He was writhing on the ground and we were falling about laughing.
All bar No2 and No5 were fixed by a visit to a gunsmith.