The AK-47 is a selective-fire, gas-operated 7.62×39mm assault rifle, first developed in the Soviet Union by Mikhail Kalashnikov. It is officially known in the Soviet documentation as Avtomat Kalashnikova (Russian: Автомат Калашникова). It is also known as Kalashnikov, AK, or in Russian slang, Kalash. No number was present in the Soviet military nomenclature for Kalashnikov's assault rifles until the adoption of the AK-74.
The improved version of the AK-47, featuring a number of refinements such as a stamped receiver (as opposed to the milled receiver of the original AK-47), a slant compensator on the tip of the barrel (to reduce recoil), an improved gas tube (without vents), and use of lighter materials to reduce weight and simplify construction.