03-03-2018, 11:43 PM
Bill,
Looking at the pictures and without any more info I'd say that bolt failed. As the bolt failed it created space, the case was no longer supported and kept expanding until it too failed. One failure occurred before the other in very quick succession. The bolt failure caused the ammo to fail. If the factory round was undersized (i.e. too much headspace) then the case would have separated and the bolt would still be intact. If the round was overcharged I would expect more signs of overpressure on the brass. This, and the history of bolts cracking in this calibre points to bolt failure.
Looking at the pictures and without any more info I'd say that bolt failed. As the bolt failed it created space, the case was no longer supported and kept expanding until it too failed. One failure occurred before the other in very quick succession. The bolt failure caused the ammo to fail. If the factory round was undersized (i.e. too much headspace) then the case would have separated and the bolt would still be intact. If the round was overcharged I would expect more signs of overpressure on the brass. This, and the history of bolts cracking in this calibre points to bolt failure.