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 model of the AK-12 5.45×39mm assault rifle is said to be more reliable, more accurate and better suited to the latest Russian military requirements. It is based on the AK-400 (Base Prototype) and it is still chambered for the 5.45×39mm cartridge. It has a cyclic rate of fire of 700 rounds per minute (RPM), a barrel length of , a maximum firing range of , and a standard magazine capacity of 30 rounds. It is also compatible using magazines from the AK-74, RPK-74, and the 96-round drum magazine from the RPK-16. The final production model of the AK-15 7.62×39mm assault