 As a result, even weakly armored light German tank destroyers such as the Marder III, which was meant to be a stop-gap measure to fight Soviet tanks in 1942, could destroy Shermans from a distance.The disparity in firepower between the German armored fighting vehicles of 1943 and the 75 mm-armed M4 was the impetus to begin production of 76 mm-armed M4s in January 1944.In testing prior to the invasion of Normandy, the 76 mm gun was found to have an undesirably large muzzle blast that kicked up dust from the ground and obscured vision for further firing.