40mm guns were among the most widely used by the United States between 1940 and 1946. The reason for their popularity was due to weapon weight and the delivery power of their shot. Shown above is a Bofors gun on a modified M3 tank chassis. This unaccepted for production model is dated at 1942 and the picture was taken at Aberdeen Proving Ground. The fire control system included a T10 computer which was a gear operated device which provided data for gun tracking.

T36 Twin 40mm AA

In 1945 this M24 was tested using six .50cal Machine Guns in a combination known as "Multiple Caliber .50 Gun Motor Carriage T77". When tested with a computing sight it was known as the T77E1. Built by the United Shoe Machinery Corporation, it was intended to be an anti-aircraft weapon. The open top on the turret was home to a two man gun crew. The T77 weighed about 38,000 ready for combat. Other than the armament, the vehicle was identical to the standard M24 light tank.

Multiple Caliber .50 Gun Motor Carriage T77

This vehicle was an attempt to place the powerful American 90mm anti-aircraft gun on a self propelled chassis for use as a tank killer. Shown above are the T53 and to the right, the modified T53E1. 500 vehicles were to have been produced, but the order was cancelled. Questions arrose about poor mobility, instability, engine cooling, crew protection, excessive height and too little weight to handle the recoil of the gun. The entire project was terminated in the Spring of 1944.