Editing M3 Lee (section)

===North African campaign===
The M3 brought much-needed firepower to British forces in the [[North African campaign|campaign in the North African desert]]. Early Grants were shipped directly to Egypt and lacked some fitments (such as radio) that were remedied locally. Under the "Mechanisation Experimental Establishment (Middle East)" other modifications were tested approved and made to tanks as they were issued. These included fitting of sand shields (later deliveries from the US had factory fitted shields), dust covers for the gun mantlets and the removal of the hull machine guns. Ammunition stowage was altered to 80 x 75&nbsp;mm (up from 50) and 80 x 37&nbsp;mm with additional protection to the ammunition bins.

Grants arrived in North Africa by the end of January 1942, and British crews began training on them. As it was developed from the World War I-era French 75&nbsp;mm gun, the British had ammunition stocks left over from then that could be used for the 75&nbsp;mm M2 gun but these suffered due to age. The armor-piercing shell for the 75&nbsp;mm was a solid shot and could penetrate around 2 inches (50&nbsp;mm) of armor at 1,000&nbsp;m, which was better than the 2-pounder guns of British tanks, but better performance was desired. Fortunately, large numbers of German 75&nbsp;mm shells were captured, and these were matched to the American cartridge. This conversion gave improved performance and was followed by an improved American AP shell design (the M61). While the Grants had been expected to be a temporary until the [[Crusader tank|Crusader Mark III tank]] with a 57&nbsp;mm 6-pounder gun was available, problems with the Crusader led to changes. The Grant became the main tank in use, and cruiser tanks such as the Crusader Mk I and II replaced the M3 light tank in British units.<ref name=TankArchives/>

[[File:SC167334t.jpg|right|thumb|Crew of M3 tank at Souk el Arba, [[Tunisia]], November 23, 1942.]]
The M3 tank's first action during the war was in 1942 during the [[North African Campaign]].<ref>Zaloga (2008) p. 28</ref> British Lees and Grants were in action against [[Erwin Rommel|Rommel's]] forces at the [[Battle of Gazala]] on 27 May. In the preparations for the battle the Eighth Army received 167 M3 tanks. The [[8th King's Royal Irish Hussars]], 3rd and 5th battalions [[Royal Tank Regiment]] went into action with Grant tanks. Retreating in the face of a large attack, the 8th Hussars had only three Grants remaining, while 3rd RTR reported losing 16.

Their appearance was a surprise to the Germans, who were unprepared for the M3's 75&nbsp;mm gun. They soon discovered the M3 could engage them beyond the effective range of their [[5&nbsp;cm Pak 38]] anti-tank gun, and the [[5&nbsp;cm KwK 39]] of the [[Panzer III]], their main medium tank. The M3 was also vastly superior to the [[Fiat M13/40]] and [[Fiat M14/41|M14/41]] tanks employed by the Italian troops, whose [[Cannone da 47/32|47&nbsp;mm gun]] was effective only at point-blank range, while only the few [[Semovente 75/18|Semoventi ''da'' 75/18]] self-propelled guns were able to destroy it using [[HEAT]] rounds.<ref>{{cite book |last1=Cappellano |first1=F.|last2=Battistelli|first2=P.P |title=Italian Medium Tanks: 1939-45 |url=https://archive.org/details/italianmediumtan00batt |url-access=limited |date=2012|publisher=Osprey Publishing |series =New Vanguard 195 |location=Oxford |isbn=9781849087759|pages=[https://archive.org/details/italianmediumtan00batt/page/n33 34]–38 |via=Archive.org}}</ref> In addition to the M3's superior range, they were equipped with high explosive shells for infantry and other soft targets, which previous British tanks had 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."<ref>{{Cite book|last=Hart|first=Liddell|title=The Rommel Papers|publisher=|year=|isbn=|location=|pages=196}}</ref>

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 [[8.8 cm Flak 18/36/37/41|88&nbsp;mm anti-aircraft gun]], in use as its secondary role of an anti-tank gun, proved deadly if British tanks attacked without artillery support.<ref>[http://nationalinterest.org/blog/the-buzz/the-m-3-grant-americas-nazi-germany-tank-killer-19126 The M-3 Grant: America's Nazi Germany Tank-Killer] - Michael Peck Nationalinterest.org, 22 January 2017</ref> 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."<ref name="stout1946_137_138">{{Cite book |url=https://archive.org/details/tanmightyfi00stou |title=Tanks are Mighty Fine Things |last=Stout |first=Wesley W. |publisher=Chrysler Corporation |year=1946 |pages=[https://archive.org/details/tanmightyfi00stou/page/n150 137]–138 |access-date=2019-07-11}}</ref>

By the [[Second Battle of El Alamein]] in late 1942, there were 600 M3s, of both types, in British service. Some of these were used for training in the UK.

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 US also fought in North Africa using the M3 Lee.

The US [[1st Armored Division (United States)|1st Armored Division]] had been issued the new [[M4 Sherman]], but had given up one regiment's worth to the British Army so that it could use them in the [[Second Battle of El Alamein]] (October-November 1942). Consequently, a regiment of the division was still using the M3 Lee when it arrived in North Africa.

The M3 was generally appreciated during the North African campaign for its mechanical reliability, good armor protection, and heavy firepower.{{efn|Initially there were problems with engine wear and suspension springs.{{sfn|Fletcher, Great Tank Scandal|page= 92}}}} 

However, the high silhouette and low, hull-mounted 75&nbsp;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 [[Spall#Antitank warfare|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 Sherman as soon as it became 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.

In early 1943, the British Eight Army's M3s, now replaced by the Sherman, were shipped to the Pacific theatre to replace some Matildas in the Australian Army.