Nah, one and the same ammo. A lot of ammo made during the World Wars that was intended for use in fixed aerial machine guns (not reachable by pilots/crew in order to clear jams) was loaded with primers given an extra heavy primer crimp to minimize jams induced by backed out primers.

"You can lead a man to logic, but you cannot make him think." Joe Harz
"Always certain, often right." Keith McCafferty