If current trends continue, missiles will replace gun systems completely in "first line" service.[citation needed] Guns are being increasingly pushed into specialist roles, such as the Dutch Goalkeeper CIWS, which uses the GAU-8 Avenger 30 mm seven-barrel Gatling gun for last ditch anti-missile and anti-aircraft defence. Even this formerly front-line weapon is currently being replaced by new missile systems, such as the RIM-116 Rolling Airframe Missile, which is smaller, faster, and allows for mid-flight course correction (guidance) to ensure a hit. To bridge the gap between guns and missiles, Russia in particular produces the Kashtan CIWS, which uses both guns and missiles for final defence. Two six-barrelled 30 mm Gsh-6-30 Gatling guns and 9M311 surface-to-air missiles provide for its defensive capabilities.
How many barrels do the guns used by the Russian defense system have?
six-barrelled