The Vehicle
Developed from the M-41 Light Tank with which it shared many parts and features, the M42 40 mm Self-Propelled Anti-Aircraft Gun, or "Duster," was an armored light air-defense gun built for the U.S. Army by the tank division of the General Motors Corp. from 1952 until 1959.
The vehicle had a crew of six, weighed 25 tons fully loaded, and was armed with two fully automatic 40mm Bofors guns with a combined rate of fire of 240 rounds per minute (rpm). For close in defense, it also carried either a .30 caliber or 7.62mm pintle mounted machine gun. The 500 hp, six-cylinder, Continental, air-cooled, gasoline engine was located in the rear of the vehicle and via a cross-drive, 2-speed Allison transmission, could attain a top speed of 45 mph with a range of 100 miles. A total of 3,700 M42s were built.