I was at the range shooting with a friend on saturday and we attempted to fire his Beretta Tomcat. It would fire the first round chambered and then misfire on the subsequent shot (no primer indentation on the chambered round). If the hammer was cocked back manually after the misfire it would then fire. It would also fire the round double action (after misfiring). The ammo was Winchester, and his primer strikes looked normal on the fired rounds. The gun is in excellent condition (if you can call a gun that doesn't fire half the time excellent). It just got back from a trip to Beretta for a magazine problem. Any ideas on what is going wrong? Shake