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 no gunsmith training to assemble a working assault rifle at home". This makes the M16 ideal for market economy production, spread among many small manufacturers around the country, using a variety of materials and manufacturing methods; this ensures it would be nearly impossible to disrupt U.S. M16 rifle production in the case of a major conflict. As of 2015, the United States military buys M4 Carbines for $647 (USD) per unit. Approximately 8 million M16 type rifles have been made worldwide. The AK-47 is a select-fire, 7.62×39mm, air-cooled, long-stroke-piston gas-operated, magazine-fed rifle, with a rotating bolt. It was designed to