Been shooting my 4 inch 45 GAP and I love it. But at least once or twice every 100 rounds the slide will lock back and not chamber another round. When I hit the slide release it racks one in the chamber. Whats up? My mags? I wouldnt think its my shooting style. Its never happened to any other handgun I've had. I was using WWB ammo. Any ideas? My XD was spotless and it happened in less than 50 rounds. Next time it shoots I'm going to mark the mag and see if it might just be the one mag causing me problems.