Looking through my stuff I found the following:
Rim: 0.580" (14.74mm)
base: 0.513" (13.03mm)
Mouth: 0.478 (12.13mm)
Bullet: 0.467"(?) 11.85mm (?) Bullet badly corroded
Case Length: 1.97" (50.00mm)
Cartridge Length: 2.56" (65.13mm)
Base on “Cartridge Cases” by Andersen, Andersen and Stromstad it appears to be a 11.4x50R Scheiben (Beaumont). I’m not familiar with this cartridge. Is that what it is? If so what can you tell me about the 11.4X50R.