M3 Lee followed by M4 Sherman
The M3 tank's first action during the war was in 1942, during the North African Campaign. British Lees and Grants were in action against Rommel's forces at the Battle of Gazala on 27 May that year. The 8th King's Royal Irish Hussars, 3rd and 5th battalions Royal Tank Regiment going into action with Grant tanks. Retreating in the face of a large attack, the 8th Hussars had only three of their Grants remaining, while 3rd RTR reported losing 16 Grants.
Their appearance was a surprise to the Germans, who were unprepared for the M3's 75 mm gun. They soon discovered the M3 could engage them beyond the effective range of their 5 cm Pak 38 anti-tank gun, and the 5 cm KwK 39 of the Panzer III, their main medium tank. The M3 was also vastly superior to the Fiat M13/40 and M14/41 tanks employed by the Italian troops, whose 47 mm gun was effective only at point-blank range, while only the few Semoventi da 75/18 self-propelled guns were able to destroy it using HEAT rounds. In addition to the M3's superior range, they were equipped with high explosive shells to take out infantry and other soft targets, which previous British tanks lacked; upon the introduction of the M3, Rommel noted: "Up to May of 1942, our tanks had in general been superior in quality to the corresponding British types. This was now no longer true, at least not to the same extent."Despite the M3's advantages and surprise appearance during the Battle of Gazala, it could not win the battle for the British. In particular, the high-velocity 88 mm Flak gun, adapted as an anti-tank gun, proved deadly if British tanks attacked without artillery support. Britain's Director of Armoured Fighting Vehicles nonetheless said before the M4 Sherman arrived that "The Grants and the Lees have proven to be the mainstay of the fighting forces in the Middle East; their great reliability, powerful armament and sound armor have endeared them to the troops."Grants and Lees served with British units in North Africa until the end of the campaign. Following Operation Torch (the invasion of French North Africa), the U.S. also fought in North Africa using the M3 Lee.
The US 1st Armored Division had been issued new M4 Shermans, but had to give up one regiment's worth to the British Army prior to the Second Battle of El Alamein. Consequently, a regiment of the division was still using the M3 Lee in North Africa.
The M3 was generally appreciated during the North African campaign for its mechanical reliability, good armor protection, and heavy firepower. In all three aspects, the M3 was capable of engaging German tanks and towed anti-tank guns.However, the high silhouette and low, hull-mounted 75 mm were tactical drawbacks since they prevented fighting from a hull-down firing position. In addition, the use of riveted hull superstructure armor on the early versions led to spalling, where the impact of enemy shells caused the rivets to break off and become projectiles inside the tank. Later models were built with all-welded armor to eliminate this problem. These lessons had already been applied to the design and production of the M4.
The M3 was replaced in front-line roles by the M4 Sherman as soon as the M4 was available. However, several specialist vehicles based on the M3 were later employed in Europe, such as the M31 armored recovery vehicle and the Canal Defence Light.