Firearm a battle rifle such as the Karabiner 98k, but the chief differences defining an assault rifle are select-fire capability and the use of a rifle round of lesser power, known as an intermediate cartridge. Soviet engineer Mikhail Kalashnikov quickly adapted the German concept, using a less-powerful 7.62×39mm cartridge derived from the standard 7.62×54mmR Russian battle rifle round, to produce the AK-47, which has become the world's most widely used assault rifle. Soon after World War II, the Automatic Kalashnikov AK-47 assault rifle began to be fielded by the Soviet Union and its allies in the Eastern Bloc, as well as
AK-12 AK-12 The AK-12 is a Russian 5.45×39mm assault rifle, designed and manufactured by Kalashnikov Concern (formerly Izhmash). It is one of the modern derivatives of the Russian AK-Pattern series of assault rifles. Kalashnikov also offers the AK-12 in 7.62×39mm cartridge, designated as the AK-15. The AK-12 project began in 2011 by the IZHMASH factory which became part of the Kalashnikov Concern as a private venture, in an attempt to participate in the “Ratnik” trials which were held by the Russian Army. It was further developed by Kalashnikov Concern, and throughout its development and evaluation stage it has received multiple modifications