The Avtomat Kalashnikova is a gas-operated, 7.62x39mm assault rifle, developed in the Soviet Union. It is the original firearm in the AK family. It was originially designed in 1945, entering military trials in 1946, and released for general use by the Soviet Army in 1948.
AKs remain the most popular and widely used assault rifles in the world, due to their reliability in harsh conditions, low production costs and availability. They have seen service in the armed forces, as well as use by insergencies worldwide.
As of 2004, “Of the estimated 500 million firearms worldwide, approximately 100 million belong to the Kalashnikov family, three-quarters of which are AK-47s”.