I have a pt1911 that i sent out to electroless nickel plate. Before it was sent out i didnt have any issues with it,now it seems like the rear end of the magazine hangs lower when inserted and gun wont chamber a round unless I push the mag up and release the slide at the same time. After first round is chambered with me pushing the mag up and releasing the slide, gun functions flawlessly. Ive tried different magazines with the same result. Basicly when I try to chamber a round slide gets stuck on the rim of the casing. Any ideas what the problem might be?