The M103 A2 Heavy Tank served in both the United States Army and the United States Marine Corps during the Cold War years of 1957-1974. However, as the idea of a main battle tank evolved, heavy tanks like the M103 became obsolete.
The A2 upgraded the A1's engine to a new 750 hp diesel engine from the M60, increasing range to 295 miles and top speed to 23 mph. The M15 Stereoscopic Rangefinder is replaced with an M24 Coincidence Rangefinder.
