AO-63 assault rifle

The AO-63 (Автомат АО-63) is a Soviet two-barrel AK derived assault rifle chambered for the 5.45×39mm round. It was designed by Sergei Simonov and Peter Tkachev, and manufactured by TsNIITochMash. It uses a side-by-side barrel configuration, and it can reach a maximum rate of fire of 6000 rounds/min when fired in two-round burst mode with a 0.01 second delay to increase ballistic performance, making it technically the fastest-firing rifle known.