Whomever rechambered this barrel to 300RUM is the idiot responsible for the explosion.

The chamber is only 1" in diameter on the encore barrels(a bolt gun barrel is 1.2" or larger) and the RUM case is .553" and that leaves .220" of steel to surround the cartridge. No wonder it exploded.

This is why TC does not chamber the RUM's. They aren't designed to handle this kind of pressure.