The Nikonov machine gun (Russian: Пулемёт Никонова) is a Soviet prototype, twin-barreled light machine gun designed by Gennadiy Nikonov at Izhmash. It was designed and manufactured during the Cold War.
The weapon had developed on its own initiative, out of competition and technical tasks. It has no bolt, but a stationary breech and movable, alternating barrels with its own gas cylinders with a piston connected to the other barrel. When one barrel fires, the other one was forced backwards, and thus made the other barrel to move forward. When firing operates a feeding device that channels rounds into the barrels, the spent casings ejected from both sides. It had a particularly high cyclic rate of 3000 rounds per minute.
The prototype is currently located at the M.T. Kalashnikov Museum in Izhevsk.