5.45 x 39.50 mm; 5.45 mm M74
Soviet ballisticians are known to have been experimenting with reduced calibres prior to 1939, but such work was abandoned during the war years. It is presumed that this work was resumed in the 1960s as the American development of the 5.56 mm cartridge became known, resulting in the adoption of this round in 1974. The existence of this calibre in Soviet use was not known in the West until 1978 and specimens of ammunition were not obtained until late 1979.
This round is of conventional rimless bottle-necked form, somewhat fatter and shorter than that 5.56 x 45 mm round. The case is of lacquered steel and a stripe of red laquer seals the case/bullet joint. The Berdan primer is of brass and there are two fireholes in the primer pocket. The streamlined bullet consists of a mild steel core filling about two-thirds of the gilding metal envelope, and a lead plug about 3 mm long in front of it. The extreme 3 mm of the tip is hollow.
|Round Length:||56.50 mm||Case Length:||39.50 mm|
|Rim Diameter:||10.00 mm||Bullet Diameter:||5.59 mm|
|Bullet Weight:||3.435 g; 10.75 g for round||Nominal Charge:||—-|
|Muzzle Velocity:||900 m/s||Muzzle Energy:||1,383 J|