Actually the Sherman used a short barreled, low velocity 75M. The British took the Sherman and ripped out the 75 and replaced it with a long barreled 76 MM and they called the tank the Firefly. The new(for then)M24 light tank also had a 75 MM but was a long barreled high velocity gun. The M41 Bulldog that replaced the M24 had a high velocity 76 MM.
No reason for pointing this out except I sometimes like to show off, the older I get the more often the urge crops up. :)
Actually there were quite a number of Shermans built with the U.S. 76mm gun, as opposed to the British 76.2mm / 17 pounder used in the Firefly.
http://en.wikipedia.org/wiki/M4_Sherman