I have what appears to be a British military blank or possibly a shot cartridge. The headstamp is "R /|\ ? C II"
The “?” is unreadable but is most likely “L”. The headstamp is too faint to scan. Althrough the headstamp indicates Cordite powder, it must be chopped cordite as I can hear it when I shake it. Or possible I am hearing shot rattle. The cartridge has a quite flat 8-petal rose crimp. It has a rounded copper primer.
The dimensions are:
C/M—O.483 (OUTSIDE JUST BELOW THE CRIMP)
DIAMETER AT BEGINNING OF NECK–0.491
HEAD TO BOTTOM OF NECK—1.584 (APPROX.)
DIAMETER JUST BEFORE NECK—0.533
Anybody have an idea of what it is?