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-9 AK-9 The AK-9 is a Russian 9×39mm compact assault rifle. Its development began when Izhevsk Machine-Building Plant (IZHMASH), now known as Kalashnikov Concern started working on a new silent, flame-less, compact AK rifle in the early 2000s. When creating the new weapon, the manufacturers have tried to surpass all available competitors, such as the AS Val and SR-3M. The basis for the silent, flame-less shooting complex rifle was designated as the AK-9, where it uses a quick-detachable suppressor. It uses the 9×39mm subsonic cartridge. The AK-9 is primarily designed for special units of the Interior Ministry and the Russian Army.