The Oerlikon Millennium 35mm Naval Gun System is a Close-in weapon system designed by Oerlikon (a Rheinmetall subsidiary) for mounting on ships. It is based on the new Oerlikon 35 mm revolver cannon land based Air defense system, and uses AHEAD ammunition. A device in the barrel measures the exact speed of each round as it is fired, and automatically sets the fuse to detonate the round as it approaches a pre-set distance from the target. Each round disperses over 150 small projectiles to strike the incoming target. Whilst these are too small to do major damage in themselves, the accumulation of damage from multiple strikes is expected to destroy wings and control surfaces, sensors and aerodynamics, causing the target to crash. Other firing modes are designed to be effective against surface targets such as small fast attack boats.

The Millennium gun is easy to install as it requires no through deck penetration and needs no supply of coolant, air or ship’s power to operate. However, it does need a power supply to recharge its batteries. Installation can take as little as sixty minutes and requires only six square metres of deck space. A Millennium gun and 120 rounds weighs 3,200 kg. The gun’s cupola is claimed to have a low radar cross section.

The weapon carries an onboard electro-optical system which relays imagery to an operator console from which it is aimed and fired. The computer system uses an open architecture and is claimed to be compatible with many existing fire control systems.

35mm caliber Swiss-german revolver cannon, it fires a sophisticated tungsten fragmentation promity fuze high explosive amunition. The rate of fire is 1050 rpm and the muzzle velocity 1170 mps.