My son got his PSA AR-9MM together today. He put a KVP 7.5 oz. heavier buffer and .308 recoil spring in it which works good. It uses Glock magazines. We took it out and tried it and it shot rounded nose full metal jackets without a problem, but the hollow points due to catching on the feed ramp didn't work as good. He has just under $650 in it. It is cheap to shoot and very little recoil. Seems like a very nice gun with even less recoil that an AR-15.