My G20 has about 150 rounds through it. Works every time with Federal ammo. Bought some underwood ammo and I am getting a failure to feed. Specific sequence of events: 1. I fire a round 2. Slide locked partially open 3. I see the next round has moved slightly out of the magazine but is at a slight angle and is stopping the slide from going fully forward. 4. If I then rack the slide, the round chambers and I can shoot normally a few more rounds. My guess is that I am limpwristing it, but I am a fairly big guy and have a firm grip (or so I thought). Is it the ammo? Is firing the round that didn't feed dangerous?