I have 16 rounds of Rem-umc 257 rem brass . I looked in cartridge of the world and it wasn't listed only 257 Roberts with a notation about a change on the shoulder angle does anyone know when this cartridge was made anything about them thanks Dan
Post a picture of the case head please.
The shoulder angle of the parent case, the 7x57 Mauser, is, I believe, 22 1/2 degrees, versus the Remington-Roberts at 15. Your brass is .257 Roberts brass, just old. Probably late '30's or early '40's.
Sorry I don't know how to add a picture. The head stamp is REM-UMC 257 REM
It is 257 Roberts. Remington legitimated the round years ago. Some cases were made with HS: 257 Rem and 257 Rem Robt. and 257 Rem Roberts.
Wow interesting, thanks guys. I did not know the origins of that cartridge.
I don't know when Remington changed the head stamp from REM UMC to R-P but I'd guess around 1950.