I was shooting my Kimber Custom II today, and about 10 times out of 150 rounds the slide would lock back as if the magazine was empty. Except the magazine wouldn't be empty. At first I thought my hand was bumping the slide stop with the recoil, but I made sure my hand was away from the stop and it still happened. It even happened when I would shoot the magazine one handed, so no chance I was nudging the slide stop into place. It happened with multiple magazines (2 Tripps, 1 Wilson and 2 Colt mags). Anyone know what's wrong with my gun? Thanks.