The Mk 44 Bushmaster II is a derivative of the M242 Bushmaster cannon. It uses some 70% of the same parts as the M242. The main difference is their callibre - 30 mm vs. 25 mm respectively. Its round, 30 mm x 173 mm, covers 1,000 metres in 0.75 seconds and 2,000 metres in 1.56 seconds. The Barrel is chrome plated for extended life. It is the standard armament of the CV90s in Finnish, Norwegian and Swiss service. It is in the process of replacing the 25mm and 40mm guns on Lockheed AC-130 gunships and will be the primary armament on the US Marine Corps' Expeditionary Fighting Vehicle.