One possible issue is the ejector worked loose. That happened on my EMP4 Champion, but I didn't have a round in the chamber. It locked when I attempted to rack the slide in preparation for cleaning after a range session. The ejectors on the original EMP's are glued in place and some of them don't hold. I sent it to Springfield and they pinned it in place at no charge. If your EMP is the newer Ronin model then I believe the ejector is already pinned, so that wouldn't be the issue in your case.