I suppose, in theory, but 7.62mm bullet is not very good compared to .223, and since it is a sniper, it should prolly stick to that until 7.62mm gets the boost it deserves.
Unique ammo would make much more sense if it's supposed to be as rare as gauss pistol for example.It's ammo that limits the use of rare weapon.
Chi si ritira dalla lottaE' un gran figlio di mignotta!
14MM AP.NATO standard .50 is 12.7 mm, Rus (Warsaw Pact Standard) I think use 14.5mm for equivalent weapons.So just make it 14MM.Closest match.