The M41A3 has a high velocity 76mm main gun. The M41 series was the first U.S. produced tank designed around the engine, rather than designing a tank and then finding an engine to put in it.
M41A3 Walker Bulldog Light Tank
This U.S. light tank was first produced in 1951 and was air transportable. Some 5,000 were built, but only a few took part in the Korean War for test purposes only. They saw extensive service in Vietnam. It was replaced by the more sophisticated and air mobile M551 Sheridan.