Even by 1944, most M4 Shermans kept their dual purpose 75 mm gun. Tank destroyer battalions using vehicles built on the M4 hull and chassis, but with open-topped turrets and more potent high-velocity guns, also entered widespread use in the Allied armies. Logistical and transport restrictions, such as limitations imposed by roads, ports, and bridges, also complicated the introduction of a more capable but heavier tank. For this reason, the US Army believed that the M4 would be adequate to win the war, and relatively little pressure was initially exerted for further tank development. When the M4 tank went into combat in North Africa with the British Army at El Alamein in late 1942, it increased the advantage of Allied armor over Axis armor and was superior to the lighter German and Italian tank designs. It spearheaded many offensives by the Western Allies after 1942. The M4 went on to be produced in large numbers. These factors, combined with the Sherman's then-superior armor and armament, outclassed German light and medium tanks fielded in 1939–42. The designers stressed mechanical reliability, ease of production and maintenance, durability, standardization of parts and ammunition in a limited number of variants, and moderate size and weight. One feature, a one-axis gyrostabilizer, was not precise enough to allow firing when moving but did help keep the reticle on target, so that when the tank did stop to fire, the gun would be aimed in roughly the right direction. The M4 retained much of the previous mechanical design, but put the main 75 mm gun in a fully traversing turret. The M4 Sherman evolved from the M3 Medium Tank, which had its main armament in a side sponson mount.

4.2 The British Army and the Commonwealth.3.7 The Caliope (US147 Upgrade Pack and USAB11 American Spearhead Force).

Largest us tank used in battle