soft ground, and were often removed, along with the front fenders, by maintenance units. The hull roof plate ranged from thick over the driver's and assistant driver's stations and turret ring, to thick over the engine compartment. The M36B1 had the hull armor configuration of the late production M4A3 Sherman tank. The sides of the M36's rounded turret were thick, constructed of rolled armor plate. A massive hollow cast counterweight was welded to the rear of the turret to balance the heavy gun. The top was thick, and the sides were thick. The rear was thick. The rounded cast gun shield was thick. Armament Primary The M36 tank destroyer used an M10A1 chassis (the M36B1 used an M4A3 Sherman chassis, while the M36B2 used an M10 chassis) mounting a large, open-topped turret mounting a 90 mm gun M3. The gunner aimed the gun using the M76F telescope. The 90 mm gun M3 was the standardized version of the experimental T7, a derivative of the 90 mm gun developed as a vehicle-mounted antitank weapon. The M36 carried 47 rounds of main gun ammunition, 11 of which were stowed in the hollow counterweight, while 36 rounds were stowed in the sponsons. For combat use, the 90mm gun M3 could fire five types of ammunition: M77 AP-T shot T33 AP-T shot M82 APC/HE-T shell M71 HE shell T30E16 (M304) HVAP-T shot The M82 armor-piercing capped shot was the main round used for engaging enemy tanks. It had a large explosive filler to increase damage after penetration. It was capable of penetrating of armor angled at 30 degrees from the vertical at and of armor at . The T30E16 HVAP shot was capable of penetrating of armor angled at 30 degrees from the vertical at , and of armor at . The T30E16 HVAP round had difficulty with the highly sloped glacis plate of the German Panther tank, so the T33 AP shot was developed to solve this problem. The T33 shot was a normal substitute standard M77 armor piercing shot that was heat-treated to improve its hardness and fitted with a ballistic windshield to improve its drag characteristics. The T33 and T30E16 were only issued in very small numbers towards the end of World War II. The M71 high explosive shell was used for indirect fire, or engaging enemy infantry, antitank guns, light vehicles, or other soft targets. Secondary The M36 tank destroyer