In the USA, max pressure of the 8x57 is held to a lower standard (by SAAMI). This is done as early J bored had a .318" bore. If you fire a .323"JS bullet, it will swage down to the smaller bore, but 99.99% of the time no damage will occur.

In the blown rifle, the bullet was still in the barrel. That just doesn't happen. 100,000+psi (enough to blow up a barrel) means that bullet isn't going to stop. No way, no how.

He can claim the barrel was clear, but IMO, that barrel had an obstruction.

Mike