7.62×54mmR [SEP] service entry
7.62×54mmR
The 7.62×54mmR is a rimmed rifle cartridge developed by the Russian Empire and introduced as a service cartridge in 1891. Originally designed for the bolt-action Mosin–Nagant rifle, it was used during the late Tsarist era and throughout the Soviet period to the present day. The cartridge remains one of the few standard-issue rimmed cartridges still in military use and has the longest service life of all military-issued cartridges in the world.
The American Winchester Model 1895 was also chambered for this cartridge per a contract
currently used military firearm is chambered for this unique Finnish cartridge. The PKM machine guns and other Russian firearms in Finnish service are chambered for the 7.62×54mmR cartridge. The standard operating procedure calls for the use of 7.62×54mmR cartridges in 7.62 TKIV 85 rifles only in emergency situations when 7.62×53mmR ammunition is not available. The reason for this is the bullet diameter difference of 7.85 mm (0.309 in) in the 7.62×53mmR versus 7.92 mm (0.312 in) in the 7.62×54mmR. Some 7.62×53mmR rounds were also loaded with an intermediate 7.88