The 5.6×39mm, also known in the United States as the .220 Russian, is a rifle cartridge developed in the late 1950s primarily for deer hunting in the USSR as well as for 100 meter running deer competitions. It is a 7.62×39mm cartridge which is necked down to hold a 5.6mm bullet (.223 caliber). It was later adopted by Finland, and by around 1965 was being produced by SAKO and Lapua. When it was introduced to the United States, Sako, and later Lapua, brass was stamped ".220 Russian".
- Parent case: 7.62×39mm
- Case type: Rimless, Bottle-Neck
- Bullet diameter: 5.67 mm (0.223 in)
- Neck diameter: 6.29 mm (0.248 in)
- Shoulder diameter: 10.20 mm (0.402 in)
- Base diameter: 11.35 mm (0.447 in)
- Rim diameter: 11.35 mm (0.447 in)
- Rim thickness: 1.50 mm (0.059 in)
- Case length: 38.70 mm (1.524 in)
- Overall length: 48.70 mm (1.917 in)
- Case capacity: 1.95 cm3 (30.1 gr H2O)
- Primer type: Small rifle
- Maximum pressure: 350 MPa (51,000 psi)
|Bullet (Weight, Type)||Velocity (ft/s & m/ps)||Muzzle Energy (Ft lbs / Joules)|
|54 gr (3.5 g) soft point||2993.4 ft/s (912.4 m/s)||1,074.6 ft lbs (1,457 J)|
In the Soviet Union, several hunting rifles were designed for this cartridge; MBO-1 target rifle, bolt-action carbine «Bars», self-loading carbines MTs-127 (МЦ-127) and MTs-128 (МЦ-128), combination guns IZh-15 (ИЖ-15) and MTs-105-01 (МЦ-105-01).
This round was also used in the TKB-022PM5 bullpup assault rifle, and in development of the standard-issue 5.45×39mm round. Likewise, its derivatives, including (but not limited to) the 6.5 Grendel and more recently, cartridges like the 6mm ARC have become highly popular in platforms like the AR-15 for superior overall performance to their traditional 5.56x45mm NATO chambering.