About says it all. CCI "fast and furious" from 2004. Loaded a round in my CZ 452 American and boom. Blew my mag to pieces and split my mag well in 2, (both are plastic). Sent the rest of box along with what was left of case and bullet, which was sitting in throat totally fine and undamaged, in to CCI. They offered to pay for the parts but already had them ordered so said just send me some .22 shells. They sent me 7 100rd boxes of mini mag target and a new box of 17hm2. I consider that fair, maybe even generous, in these times of shortage and demand. Can't post pics here but put the complete story, with pics, on Outdoor life's question and answer forum.
CCI's explanation was the round was exposed to either extreme heat or chemicals causing the neck to become brittle. I only bought them 2 years ago along with 2 other boxes off a fella so I have no clue how they were treated.