6.5×50mmSR Arisaka - Wikipedia
The 6.5×50mmSR Arisaka (designated as the 6,5 × 51 R (Arisaka) by the C.I.P. [1]) is a semi-rimmed rifle cartridge with a 6.705 mm (.264 in) diameter bullet. It was the standard Japanese military cartridge from 1897 u...