You got me there! I have no reason to disbelieve the fellow but no, I am not absolutely sure. He does present as a straight talking guy. I'll keep looking for verifiable evidence. Anyway, he said the striker shaft broke off behind the collar. I asked and he didn't answer so I don't feel free to quote him.

By the way, it is comforting that you armourers have not heard or seen this sort of thing before. My first thoughts when I hear about this sort of thing are, "oh heck, could this happen to me?"

But here's a thought; if a primer ruptures at 48,000 CUP, the force acting on the striker could be as high as half a ton (as unlikely as that may be). Thinking about it, if high pressure builds up inside the bolt, the striker could be driven back quite fast providing a hammer effect when it reaches the end of it's travel. And we all know what shock loads can do to hard steel. Ever had a chisel fracture and drive a shard into your ribs? I haven't, thankfully but know of a few instances.