The M3 AT Gun was an anti-tank gun that was used by the United States during World War II.


The M3 could fire 37 mm rounds at up to 8.8 kilometers.[1] The M3 required a crew of around four to six men and it could penetrate up to 60 mm of armor at 457.2 meters. The total weight of the M3 system was 413 kg and the total length was 3.9 meters.

The gun had a maximum firing range of up to 6.4 kilometers and a total traverse of 60 degrees. The gun also had an elevation range from -15 degrees to +15 degrees.[2] The muzzle velocity of the M3 was about 880 meters per second.

The M3 caused mixed emotions among its crew. It generally depended on where the gun was used. On the Western Front, the M3 was disliked because of its inability to effectively knock out heavier German and Italian tanks. In the Pacific Theater however, it was generally accepted because it could kill the extremely light Japanese tanks, it was light weight and highly mobile, both good qualities for navigating thick jungles, and it could double as an anti-infantry weapon through the use of a "canister" round which was a round filled with small balls similar to a shotgun that would kill and maim any infantryman caught in its crosshairs. One of its drawbacks though was that it had a very small shield and thus the crew were very exposed to enemy fire.[3]


The first variant of the M3 series that actually improved upon the infantry version of the gun was the M3A1 which had a modified barrel that was fitted to accept a muzzle brake. The next two variants were the M5 and M6 which both were tank mounted variants and had modified barrels to fit tanks. The most notable vehicle to use these two guns was the M3 Light Tank. Another vehicle that had the M5 or M6 mounted was the M6 Gun Motor Carriage.


M6 Gun Motor Carriage

An example M6 Gun Motor Carriage mounting the M5 version of the M3 AT Gun.

The M3 AT Gun was first developed around 1937 as the American military saw the need for a weapon that could compare respectively to the German PaK 35/36 in terms of combat effectiveness as it this time, the US Military had none. Production quickly began in 1940 with hundreds of units being shipped out to US troops before the American entry into war. The M3 was removed from service in North Africa temporarily as it was demonstrated that a more powerful AT gun was needed to kill German tanks but the US marine corps used it until the end of the war without pause and the M3 was later reintroduced in Italy, 1943. In total, about 18,000 M3s were produced during the war.


  1. Lüdeke, Alexander. Weapons of World War II. Parragon Books Ltd (2007), Page 169

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