First of all anyone who sees the picture of the cartridge will be able to point out that the cartridge actually blew up and he was hit with brass shrapnel.
He claims he attempted to chamber the cartridge 3 times before it went off.
Assuming it wasn't a hangfire what could have caused the round to go off?
Someone on another forum saw a picture showing a properly struck primer.


http://www.cbc.ca/news/canada/new-br...face-1.3811399