Sometimes when a round does not chamber properly (for any number of reasons), the brass tip can become damaged. It doesn't happen very often but I have experienced it a handful of times. But I have never before seen a gouge: (1) that deep; or (2) on both sides of the round. Not sure how that even happens.

I was firing the pistol and the slide failed to go 100% into battery. As I pulled the pistol back towards me, the slide slid into battery on its own. So I thought everything was good. But when I went to fire the next round, I had a dead trigger. When I ejected the round, I saw this. I was anxious that I might have damaged some portion of the feed ramp or chamber or extractor. But everything looked good from what I could tell and the pistol functioned fine for another 50 rounds or so. And when I got home later and disassembled and cleaned the pistol, everything was indeed fine. *shrug*