At a local IDPA shoot today, and one of my club members, who I've known and shot with for a while tells me, "I'm switching to 45, you wanna try out these 9mm SWCs?" Sure, so I try some out, they punch nice clean holes, and run well in my gun. Inspect the empty casings, and see a little bit of swelling around the case mouth. (Shoulda heeded that :rolleyes
Not seeing any swelling that looked excessive, or was stretching the brass to extremes, from what I thought, I shot away. Until...
Which, scared me a bit. Felt a pop in my hand, and it shot my magazine out. Opened my hands to see that my backstrap looked like this;
It split straight down the inside of my mag well, and across the top of my trigger rail on the side. The frame is all polymer, and I have some plastic weld left that I used to do the grip in the first place. I'm going to try chucking that ammo, and welding this frame back together, though. A lesson learned in reading casings!