United States, 1940-1945 (66MB download, please be patient!)
The M3 37mm Anti Tank gun was the main anti tank gun for the US Armed Forces in the beginning of the war. It was very effective early on due to its high penetration compared to its contemporaries. It also was notable due to it having canister shot, which was a great help during jungle fighting in the Pacific. It also equipped several armored vehicles, including light tanks like the M2, M3, and M5, medium tanks, like the M3 Lee, as well as the first US Gun Motor Carriage, the M6. The M8 Greyhound armored car also used it. However, by 1942, the M3 was being outstripped by the armor developments of the Axis nations, leaving infantry and light armor units without an adequate way to deal with enemy armor. For infantry units this would come in the form of an American made 6-pounder, called the M1 57MM AT Gun<br>(UK 6-Pounder), but light tank squadrons had to wait for the very end of the war to get their new light tank the M24 Chaffee