M3 Stuart TroopBolt Action M3 Stuart Troop En 402013001 : Before the war much effort went into building light tanks, which were felt to have a role analogous to cavalry in an earlier age. Once war began these precepts were quickly brought into question, and the need for more heavily armoured and better armed tanks became apparent. The M3 was derived from the pre war M2A4 light tank: it retained that tank? s 37mm gun and 3 hull mounted machine guns. The British Army