Here's the deal: I had a weird ammo-related problem this past weekend. It locked-up my G22 tight, and it took a while to safely clear the stoppage. I had a pretty good idea of what the problem was once I got the weapon open, having seen something similar before, many years ago. An in-depth examination of the cartridge afterward confirmed my suspicions. I'm going to describe the symptoms and show a few photos of what I found; you get to guess exactly what caused the problem (if you'd like). Set up: Glock 22 in .40 caliber. Ammo was Remington/UMC 180 grain JHP (sold in a 100-round double-stacked-tray value-pack box). Indoor range, a series of 2-shot drills at 10 yards. A dozen shots into the magazine, I get a "click" instead of a bang. I know I'm not empty yet. Following the range safety protocol for a potential hang-fire, I wait 30-45 seconds with the weapon under full control, pointing at the backstop. I then try to eject the cartridge onto the benchtop. No go. The slide will not budge. It is fully closed and locked, but will not move more than a fraction of an inch. I remove the magazine and signal the RO that I have a problem. When he arrives, I tell him what has occurred, and that I can probably handle it but I wanted to keep him informed on what was going on. He suggests banging the slide on the rear edge of the bench to get it to unlock and open. I counter-suggest removing the slide assembly and tapping the barrel hood downward (with a plastic mallet) to unlock it and remove the jammed round, all while keeping it pointed downrange. He agrees. I pop the slide off, take the mallet and begin tapping on the barrel hood. At first, it does not move at all (!). After a few taps, it slowly begins to move downward to the unlocked position. Once it is fully unlocked, the barrel moves freely forward, and the round slides out onto the carpeted benchtop, unassisted. No problem is found with the gun, which is assembled and fired again later with no ill effects. In examining the round, I note the rear of the round is slightly discolored, and the primer is partially protruding from the primer pocket (which I assume is what jammed the slide closed). Here are the photos: So, what do you think is going on here? Post your guesses and reasoning below! .