Twin 40mm Self-Propelled Gun

By the time the M42 "Duster" anti-aircraft weapon system was deployed in 1953, the Soviet Union had developed high-speed aircraft that were too fast for the Duster to track. The Duster, however, found its role in the dense jungles of Vietnam. Its awesome firepower proved effective in suppressing enemy ground fire on convoy duty and in fixed defensive positions. ACF industries of Berwick, Pennsylvania, built M42 Dusters in the 1950s.About the M42A1 Duster First accepted: 1951 Manufacturers: Cadillac Motor Car Division of General Motors and ACF Industries, Inc. Total Built: 3,700 Crew: 6 men (Commander and Driver in vehicle; Gunner, Sight Setter, and two Loaders in turret) Armament: 40mm Dual Automatic Gun M2A1 "Bofors" in turret, and .30 caliber M1919A4 machine gun mounted at front or rear of turret Armor: Between .3" and 1" all around vehicle Engine: Continental AOS-895-3; 6 cylinder, 4 cycle, opposed supercharged gasoline Horsepower: 446 at 2400 rpm Maximum road speed: 45 mph The name "Duster" came from the huge clouds of dust raised by the vehicles as they moved at 45 mph over crude dirt roads in the Mekong Delta. The gun turret could rotate 360° and elevate to 85° when deployed against aircraft. However, it was its ability to depress the guns as low as -5° that made it invaluable in close jungle warfare. Twin Swedish Bofors 40mm cannons fired a blistering 240 rounds per minute. Crewmen loaded the guns by hand with four-round clips. Storage boxes on the vehicle's hull kept 100 clips within close reach.