I just purchased a used P3AT from a local gun shop. Took it to the range to try it out and the first few shots went off fine, but the 4th caused the mag to release and the next round didn't chamber. I gave it a good smack, pulled back on the slide to chamber another round and it released again. On average it releases about one out of every 3-4 shots. Since I'm using the standard mag I can hold it in place using my ring finger, but that's not how the gun is supposed to function. I have a new mag coming from Kel Tec to see if that fixes the problem. If not any suggestions?