Just tried to remove the firing pin and see if 9mm rounds can be chambered from the magazine into a 7.63 chamber, and at least that part of it is possible.
I quess the barrel could survive it, as every barrel extend a bit as the bullet passes trough. But on the other hand, this would be more than just 'a little bit'.. perhaps the metal is softer than whats used today, and by that making it possible?
I would think when firing a revolver where the bullets get stuck in the barrel, the shooter would hear a significantly less bang than normal? (especially if it was something like a Nagant)
Perhaps close to the KGB silenced amunition, where no gass gets out of the shell at all..
http://world.guns.ru/ammo/sp-e.htm
btw. Had a bullet stuck on a Mauser 1914 once, but did not notice any twist to left. Got so scared by all the sparks, that I probably would not notice much anyway..
