The 5.6×39mm, also known in the U.S. as .220 Russian, is a cartridge developed in 1961 for deer hunting in the USSR.

While it originally re-used 7.62x39 cases, once it became popular enough commercial ammunition started being manufactured, both in the USSR and in Finland.

[4][5] When it was introduced to the United States by SAKO it was stamped .220 Russian.

Lapua later changed the designation to .220 Russian for the American market as well.

[8] 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,[9] MTs-5-35[10] and MTs-105-01 (МЦ-105-01).