 Armored infantry battalions were also eventually issued three of these Shermans.The 105 mm-armed variants were of limited use against enemy tanks due to the poor anti-armor performance of the howitzer, which was not intended to fight other tanks, though a high explosive anti-tank (HEAT) round for the 105 mm howitzer was available for self-defense.The turret armor of the 75 mm and 105 mm-armed M4 ranged from to thick.