A few years ago an officer near here lost his Glock during a struggle. The bad guy tried to pick the pistol up. All the officer could do was try to hold the gun on the ground as the bad guy had the better grip on the gun. Another officer came up and put his Glock in the bad guys back. The bad guy would not give up the fight so the officer pulled the trigger. Nothing happened. He racked the slide and put it back in the badguys back and pulled the trigger again. Still no bang. He gave up trying to shoot him with the Glock and just hit him over the head with it ending the fight. When the gun was inspected everything appeared to work fine. The problem turned out to be that when he pressed the gun to the badguys back the slide was displaced backwards a little ways and the gun wouldn't fire. I also had a friend whose Glock jammed several times while qualifying. I guess I wouldn't feel very confident taking a pistol on patrol that I know has jammed on me before.