TypeAssault rifle
Place of originSoviet Union
Production history
DesignerSergei Simonov, Peter Tkachev
Mass3.68 kg (8.1 lb)
Length890 mm (35.0 in) (Standard)
1,025 mm (40.4 in) (Extended stock)
Barrel length430 mm (16.9 in)

Rate of fire850 rounds/min
Effective firing range850 m (930 yd)
Feed system45-round detachable box magazine
SightsIron sights, Picatinny rails for various optics

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.


The AO-63 assault rifle was used by the Spetsnaz during the Abakan trials in May/June 1986, in search of a more accurate alternative to replace the standard issue AK-74. It was described in the official report as being highly accurate as well as simple and reliable; despite its accuracy and performance, it was later dropped out of the competition for unknown reasons, with the AN-94 emerging victorious.


The AO-63 is a gas-operated, 5.45×39mm caliber, twin-barrel assault rifle derived from the Kalashnikov rifle. The weapon has side-by-side barrels with the right barrel predominant, twin rotating bolts/gas pistons and ejects from both sides. The trigger group has a 3-position selector on the right side of the receiver; the first is semi-auto firing one barrel, the second in full auto firing both barrels with a 0.01 second delay, the third is unique as at first it fires a two-round 6000rpm burst then one barrel in 850rpm full auto. The magazine is unusual as it has the main double column holding 30 rounds with a single column holding 15 rounds.