The 7.62×54mmR is a rimmed rifle cartridge developed in Russia in 1891. It was originally designed for the Mosin-Nagant rifle and has been used in various military firearms, including machine guns. The cartridge features a bullet diameter of 7.62 mm and a case length of 54 mm, making it one of the oldest military cartridges still in use today. This cartridge is known for its accuracy and effective range, making it popular among military and civilian shooters. It has been utilized in numerous conflicts and is compatible with a variety of firearms, including the SVT-40 and PK machine gun.