This cartridge was originally developed during mid-1960s as a direct rival to the US 5.56×45 M193 carttridge then in use by US Army. Originally it featured a long, low-drag bullet with mild steel core and a hollow cavity in the nose to provide optimum balance, and a laquered steel case. This version was adopted in 1974 and oficially designated in USSR as 5.45mm 7N6. Later on, this cartridge was generally replaced in production in Russia by 7N10 ammunition, which has improved penetration thanks to harder steel core. Other bullet types in the 5.45×39 range of military ammunition include tracers, armor piercing and subsonic cartridges (for use by Spetsnaz troops in silenced AKS-74UB compact assault rifles).
The 5.45×39 is still a general issue caliber in the Russian military and a few of other ex-USSR republics. In most other the ex-Warsaw pact countries this caliber was gradually replaced in service with 5.56×45 NATO ammunition and appropriate weapons. It is also produced for civilian use with lead-core bullets.
|Designation||Bullet weight, g||Muzzle velocity, m/s||Muzzle energy, J||Comments|
|5.45×39 7N6||3.43||880||1328||bullet with mild steel core|
|5.45×39 7N10||3.62||880||1400||bullet with enhanced penetration|
|5.45×39 7N22||3.68||890||1430||armor-piercing bullet with hardened steel core|
|5.45×39 7U1||5.2||303||239||subsonic, for use with silenced AKS-74UB compact rifle only|