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 be a simple, reliable automatic rifle that could be manufactured quickly and cheaply, using mass production methods that were state of the art in the Soviet Union during the late 1940s. The AK-47's barrel and bolt were milled out of a steel billet and hard chromed. Its receiver was originally designed to be stamped from sheet metal with a milled trunnion insert. However, there were many difficulties during the initial phase of production causing high rejection rates due to faulty receivers. Instead of halting production, a heavy forged steel machined receiver was substituted for the sheet metal receiver. This was