The 7.62x39mm is a small, stubby .30 caliber 
round developed by the Russians for use in 
assault rifles and light machineguns.

    The Kalashnikov AK-47 and AKM automatic 
rifles are most often encountered in 7.62x39mm.  
The cartridge has become popular among American 
shooters due to the abundance of inexpensive 
Russian SKS rifles (and Chinese copies) that have 
been imported.  As the SKS is a semi-automatic 
ONLY design, it subject to fewer special BATF 
restrictions and is available readily.

    The cartridge is slightly less powerful than 
the .30-30 Winchester, but significantly more 
powerful than the .357 Magnum.

    The 7.62x39mm was the target of 
anti-2cnd-Amendment politics in 1993, when a 
California pistol manufacturer produced some 
experimental handguns in this caliber.  
Unfortunately, this allowed the BATF to 
technically classify the 7.62x39mm as a pistol 
cartridge, preventing importation of inexpensive 
steel-core ammunition (steel core infers "armor 
piercing" handguns).  The result of this action 
was that the costs of 7.62x39mm ammunition to the 
sportsman and enthusiast tripled, with no 
positive crime-fighting result gleaned.