The AK-630 (Avtomat Kalashnikova, 6 barrels, 30mm) is a 30mm Gatling gun used on ships of the Russian navy as a terminal defense against anti-ship missiles and close-in aircraft. It was the first CIWS system operationally deployed, even before the US's Phalanx system. Except on light missile boats, they are generally mounted in pairs, with the associated Bass Tilt fire control radar nearby. Unlike most Gatling guns, these are gas-operated and do not require external power to fire. While this slightly complicates turret design, since there needs to be a way to force gun gas out of the turret, it eliminates the need to run fragile electrical cables to the weapon.
Most ships of frigate size or larger have at least four of these. They were first installed on the Kresta II-class ASW destroyers, and were subsequently retrofitted to several Kynda class cruisers and Kashin class destroyers. All later classes of major Soviet and Russian warships carried them as well, until they were finally replaced by the CADS-N-1 CIWS on the Kuznetsov and later Sovremenny and Kirov class units.
As a CIWS, the AK-630 is consistently rated as inferior to the American Phalanx and the Dutch Goalkeeper, primarily due to its off-mount fire control. However, a single AK-630 dual mounting installation would attack a single target with two streams of shells, somewhat mitigating its lower accuracy.