On the second-to-last-round of every magazine load, I get a failure to feed. It jams the bullet into the upper edge of the chamber and crease the nose on my Federal American Eagle FMJ. All other rounds before and after this one in the magazine work fine, just the second-to-last jams EVERY time. While jammed, if I rap the slide, it finishes feeding the round and works fine. I have only the magazine that came with it, or I'd test it with another one. Magazine spring tension or something? Any ideas on how to fix it?