10 factory new Starline unprimed 45 Auto Rim (45 AR) brass revolver cases. Uses large pistol primers
Odd numbers of cartridge cases is the result of bulk bagging. Bulk brass is sold in barrels, generally by weight and it is not uncommon for odd number of pieces remain.
HISTORY: Following WWI, Peter’s Cartridge Company developed the 45 Auto Rim which is a rimmed version of the 45 Auto so surplus revolvers purchased by civilians can shoot them without using moon clips.