I've told this story before. During the short period I was in Iraq, we carried M9s everywhere on base, but weren't supposed to chamber a round until we were going "over the fence". I've always complained about how little handgun training the Army gives its troops, and this was one example. Had a new WO1, fresh out of flight school and on her first deployment. Going into any common area, we were required to clear our weapon(s) into a sand barrel before entering. Usually the procedure was: remove the magazine, rack the slide, check the chamber, pull the trigger on an empty chamber (I don't know why we did this with a SA/DA pistol). One day after a mission, a group of WOs was going to the mess hall. She got to the sand barrel, racked the slide, pulled the trigger, BANG! Startled, she racked the slide again, pulled the trigger again, BANG! She got off one more shot into the sand barrel before one of the other WOs could get to her and get the magazine out of her pistol. The Ugandan security guard wet his pants...
