The AK-47, officially known as the Avtomat Kalashnikova (Russian: Автомат Калашникова, lit. 'Kalashnikov's automatic [rifle]'; also known as the Kalashnikov or just AK), is a gas-operated assault rifle that is chambered for the 7.62×39mm cartridge. Developed in the Soviet Union by Russian small-arms designer Mikhail Kalashnikov, it is the originating firearm of the Kalashnikov (or "AK") family of rifles. After more than eight decades since its creation, the AK-47 model and its variants remain one of the most popular and widely used firearms in the world.