USCCo Headstamp

With center fire cartridge a UoverS primer stamp designates smokeless powder and a US primer indicates black powder or Lesmok. But what about the rim fire, indented US vs raised US is there a way to determine black powder from Smokeless? Also I have some of the USCCo with original copper primer with no stamp? reloads? they don’t look like it. I am basing this on a 1914 US catalog. thanks Pete. Any suggestions would be highly valued. Thank You Vic

Vic–The impressed (not indented) “US” on rimfires could be either blackpowder or smokeless, but ALL raised “US” are black powder.

On centerfires, I think both intertwined “US” and plain “US” as well as underlined “US” are all smokeless loads. Unmarked primers are black powder.

In some calibers, USCCo used un-monogrammed primers in smokeless loads…the .30-40 Krag is one of them…I have probably 25 different USCCo loads in this caliber and none have the monogrammed primer…Randy

I just got a 1914 catalog for USCCo and it clearly pictures the centerfire primer with the US stamped on the primer for Black or Lesmok. But the smokless shows UoverS. Is this real or just an artists interpretation??

Vic–I based my answer on what U.M.C. did, as that is the company I know best. If the catalog shows the primers and says what they are used in, I think you can trust it to be correct. At least, everything shown in the U.M.C. catalogs seems to be accurate, so no reason to think the U.S.C.Co. catalogs would be any different.