That was a great video David. However, that was an obstructed barrel test, not a case-rupture test. The brass would still act as a gasket and seal the chamber. And remember that chamber pressures dropped by the time the bullet hit the obstruction compared to a partially lodged bullet followed by a case rupture.
A bullet was driven 10cm from the muzzle to act as an obstruction, the rifle clamped, then fired. It showed the strength of the barrel from bursting. Its also unclear if the bullet dislodged the obstruction as the rifles that did not burst recoiled backwards. Notice that the ones that busted didn't move in the vise.
Still an interesting test, but not representative of a ruptured case and gas handling.
