For what it's worth, I believe the original specifications for 9mm NATO involve a higher pressure than standard commercial 9mm (effectively +P, i.e., probably n

For what it's worth, I believe the original specifications for 9mm NATO involve a higher pressure than standard commercial 9mm (effectively +P, i.e., probably not something to fire a C&R WWI Luger, but again not quite a .357 magnum).