Hi, I had the same problem. It was diagnosed by the late Steven Camp over the internet. He was quite a guy. The extractor has insufficent tension. When the magazine is full it holds up the round and it is ejected normally. If weak on the last round it pulls out the shell and it slides down before it hits the ejector. My MKII was bought used from a gun store and their GunSmith fixed it. It had an outside extractor and he said (?) he removed some metal from the inside of the extractor increasing tension. On an inside extractor I think you can add tension by bending it like the 1911. Brownell's sells a tool for this. I'm not a GunSmith and don't play one on the internet so you better ask someone smarter than me. I think this is more normal than people know . Yours is the 3rd pistol I've run into with this problem. Regards, Mike