Reloaded 9mm the other day, and shot them through my S&W 9mm 2.0, with the pictured results. Both were military brass which showed nothing abnormal upon initial examination, and sized, loaded and chambered normally. Fairly stiff load.
After the event, I checked my stash of 9mm cases and found several more with the same headstamp. Upon examination, I found that they were expanded to the point that they would not enter the chamber of my pistol. My guess is that these were fired in a subgun or something with an abnormally large chamber, and when I resized them the sizing die set up a stress riser at the case web.
No harm done, but I just thought I’d post a heads up.