Took my new Thunder 40 UCP and put 100 rounds thru it. First 60 rounds went fantastic. Loaded the next mag and the third round jammed going into the chamber, cleared it and finished the mag (7 rounds) with no problems. reloaded, fired the first 2 rounds, the third jammed in the same place, again finished off the mag with out any problems, the next mag was the same, and the last ran thru with out any problems. I only had the 1 mag (left the other at home in the box ) When I got home and cleaned the gun, I found no burrs or anything else that would cause a jam. I'm thinking it might be the mag. Any ideas? The mag seems to "float" while in the gun.