There have been so many...... ROFL !!!
I was once shooting off my big mouth at the range about how my Norc 1911 Govt wasn't the nicest, most accurate pistol ever, but it NEVER jams. I hand it to a guy (cop) to try out. The thing jams on the second round.
I can't comment on the circumstances, but I once fired (on purpose) a 300 win mag with a muzzle brake on it inside a very small enclosed space with no hearing protection on. That's one to never repeat, trust me.
I was out deer hunting with my Browning BAR semi-auto and spotted a deer. All my cartridges were in my pocket. No wait...it gets better....did that TWICE in the SAME DAY !!! Shut up Rottweilerboy !!! LOL !!
I was new to bullet casting and thought I could get away without using gas checks on the 30-30 rounds I was shooting out of my Winchester 94 lever. Me + cleaning rod and brush + MANY hours = You could see the barrel rifling again.
I didn't know the first thing about an SKS. I bought one and started to take it apart to clean it. I can't remember why I wanted to take it off, but couldn't get the front sight off. In a moment of frustration, I took a grinder to it. As it turns out, that spring inside is a necessary part. LOL. I gave the gun to Haywire1 for parts.
I drove 1 hr 10 min to the range with about 10 guns and left ALL my ammo sitting on the garage floor. I was so mad at myself, I drove all the way home, grabbed it, and drove back to the range. 4 hrs and 40 minutes drive time for a few hours of shooting.
I once lined up a bunch of milk jugs full of water on a plank. I laid down and shot them at a distance of about 2 ft with my 44 mag revolver to see how many it would go through. If it wasn't the middle of winter, the shower I took wouldn't have been so bad.
I was using the floor of my service truck as a casting bench, and the power inverter to run the lead pot. My retired neighbor came over with his dog and started chatting to me. Rather than being distracted while casting (safety first !) I decided to shut off the inverter until he had left. I jumped into the back of the truck, clicked off the inverter. When I took a step back, I knocked 5 lbs of molten lead all over the back of my truck, the driveway, and splashed the side of Mrs BSD's 1 year old van. By some miracle, I didn't get my neighbor or the dog. Many hours with a pick and needle nose pliers, and I had most off it off the driveway.
The one I'll enter with.....
I was making (welding) a tool to make the trunnion straps for mini-canons. I set the garage and myself on fire. One 20 lb fire extinguisher, a trip to the local emergency room, a few trips to the burn unit downtown for cleaning and debridement, lots of drugs, many hours of cleaning, and 3 weeks of painful healing, and all was good again !!!