It does not surprise me that the case head and body are pretty much the same between 7x57 and 8x57. The narrower bullet and different shoulder would allow it to telescope just a little deeper into an 8x57 chamber.
The bullet is a millimeter smaller. There's only a whisper of rifling contact, if any. Therefore it keyholes, and has the chamber pressure of a smoothbore musket. Between leakage around the bullet and leakage around the neck, it only made enough pressure to push the primer out, but not enough to bust the case head. Bet it was gassy to shoot.
Lot better than the other way around.
The bullet is a millimeter smaller. There's only a whisper of rifling contact, if any. Therefore it keyholes, and has the chamber pressure of a smoothbore musket. Between leakage around the bullet and leakage around the neck, it only made enough pressure to push the primer out, but not enough to bust the case head. Bet it was gassy to shoot.
Lot better than the other way around.
