Hang fires can ruin your day.
The wife and I were at the range one day. She had shot several rounds through her Semi-auto 30-06. Then a click. At first she thought she was out of ammo, then she remembered she had a 10 round magazine, and had only fired like five shots. She had turned and was looking at me ready to ask what to do now. Her gun safety training made her keep her gun pointing down range. BANG, it went off. Recoil slammed it back into her ribs, but she clamped down on it to hold it steady, as it chambered another round. I came over and unloaded the gun. She was shooting factory ammo. She complained with her ribs hurting for a week. Never figured the cause of the hang fire.