Thanks to all. I looked at the link above provided by MikeL2 and the ammo was from the 1946-1960 era. It has the round-nose Mushroom Core-Lokt bullets. I fired one out of my Savage Axis rifle with 24" 250 Savage barrel and it chronographed 2,911 fps. I believe the powder used was a non-canister version of IMR 4895.
