I just bought a Combat master VI. I shot the weapon once without a problem. Took it apart to clean it and now I get a stoppage on every round. The spent case stays in the barrel, and the slide will not cycle all the way back. I've taken it apart and re-assembled many times, but it still will not function. I also ruled out ammo problems. Could this be a mag problem, ejector problem, springs? Any info would help. Thanks