Courtesy of WiscoDave
Having worked in an Army ammo plant the process isn't unfamiliar to me, the machinery is just much smaller and there aren't as many steps. Our transfer presses cupping and shaping the grenades were rated at 300 tons per square inch and shook the ground when the punches hit the die tables.
The mortars were cut from billets and ran through a hot press before machining.
But all in all it was the same basic process, except for the loading part. Our parts were sent to a separate facility for the explosives.