which indicates that it is intended for the 30-06. Some may have been made in the 30-03 round, but the makings certainly indicate this one is not. Also the OP does not make clear that this is not a replica which were all 30-06. If the gun is original I would make that the headspace is still good. Some of these rifles were damaged by firing 8mm mauser ammo in the 1920's by people not knowing any better. The basic rear locking design does make increased headspace possible over the space of a hundred years of use.marked 30 Govt 06.