Diagnosing the cause of mangled cases
Recently a fellow took his Dan Wesson Pointman PM2 to the range to have some fun. What he got instead was mangled brass and constant jamming. He posted a couple of pictures showing the cases.
I looked at the pics and immediately diagnosed an extractor that was losing control of the empty cases during recoil causing them to not eject. The empty cases would then sit on top of the next round in the magazine as it was being fed. The empty cases would then get slammed into the barrel hood. I've personally experienced this specific malfunction in the past so was confident in my diagnosis.
https://i.imgur.com/L8TVLCf.jpg
https://i.imgur.com/GBtEB5H.jpg
Eventually the fellow set about removing the extractor from the slide and discovered the firing pin stop had suffered a catastrophic failure. While my initial diagnosis was technically correct, it wasn't due to a bad extractor as you can see in the picture below. The broken firing pin stop allowed the extractor to clock which caused it lose control of the case.
I don't think I've ever seen a firing pin stop fail like this one.
https://i.imgur.com/20BVOvK.jpg
