The Kalashnikov assault rifle went into mass production in February 1947. In 1949, the weapon was adopted by the Soviet Army. An estimated 100 million AK-47s have been built worldwide since then. In comparison, about 7 million M-16 assault rifles have been made. The M-16 is the Kalashnikov's main Western rival.
More than a dozen modifications have been developed for the AK-47, including one with a curved barrel allowing tank crews to shoot around corners. That particular modification, however, never went into mass production. The rugged, reliable and easy-to-use AK-47 is still favored by an assortment of armed forces, guerrilla groups, terrorists and even common thugs in at least 55 countries.