Has anyone see case failures where the entire case was significantly elongated? (UPDATE: Commenters have pointed out that these are normal-sized cartridges jammed into separated case heads that remained in the front of the chamber when the new round was being chambered) I reviewed the above photo in an email yesterday. Tom wrote …
This photo is of some A-MERC 5.56 rounds that went through my Mini-14 yesterday. On two occasions, the round fired and the case completely separated. When the bolt cycled, it extracted the base of the case while the front stayed in the chamber. When the bolt shoved the next round into the chamber, obviously it did not go into battery. The shooter cycled it by hand which resulted in the extraction of the weird looking long rounds. It wasn’t until it happened a second time that we looked at the extracted round and decided something was not going right. We found several cases like the one on the right that had split but not completely separated. Some splits were circumferential like those shown, but there were several with longitudinal splits.
When I got home, I did a search for A-MERC and found numerous complaints, dating back to 2006. Nearly all were about the quality of the brass, including primer pockets out of alignment, splitting of the case mouth when reloaders inserted bullets, splitting of the pockets when primers were inserted, and so on. Complaints weren’t limited to 5.56, but included other calibers as well.
To be fair, I don’t remember where or when I got this stuff. A-MERC may have cleaned up their act, but to be safe, I’m going to have a little cull session before my next range trip.