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
Comparison of the AK-47 and M16 the RPD light machine gun. Shortly after World War II, the Soviets developed the AK-47 assault rifle, which would quickly replace the SKS in Soviet service. The AK-47 was finalized, adopted and entered widespread service in the Soviet army in the early 1950s. Its firepower, ease of use, low production costs, and reliability were perfectly suited for the Red Army's new mobile warfare doctrines. In the 1960s, the Soviets introduced the RPK light machine gun, itself an AK-47 type weapon with a bi-pod, a stronger receiver, and a longer, heavier barrel that would eventually replace the RPD light machine gun.