I bought and modded my retailiator recently, just an AR and lock and jam door removal. The prime is no longer smooth, and has almost a crunch sound when coming over a bit of resistance at about the 1 inch into the prime. Ive reassembled the blaster about 3 times, and can not seem to fix the problem. It reminded me of the same problem with gen 1 recons after modding. Any idea what to troubleshoot?