Tanks of the United States US allies it was also used in conflicts beyond World War II. A 24-volt electrical system was used in the M4. Early Shermans mounted a 75 mm medium-velocity general-purpose gun. Although Ordnance began work on the Medium Tank T20 as a Sherman replacement, ultimately the Army decided to minimize production disruption by incorporating elements of other tank designs into the Sherman. Later M4A1, M4A2, and M4A3 models received the larger T23 turret with a high-velocity 76 mm M1 gun, which reduced the number of HE and smoke rounds carried and increased the number of anti-tank rounds. Later, the M4 and
History of the tank was considered to be up to 10 tons, the medium (produced by the British) was roughly between 10 and 25 tons, and the heavy was over 25 tons. For World War II, increased weights resulted in the light tank being over 20 tons, the medium over 30, and the heavy, developed toward the end of the war, over 60 tons. During the period between the world wars, the weights of the classifications varied generally within these extremes. The U.S. National Defense Act of 1920 placed the Tank Corps under the Infantry. The Act's stipulation that "hereafter all tank units shall