 For those vehicles that did not have a muzzle brake, once the Armored Force began to accept M4s, it was recommended that tank commanders stand outside the tank and "spot" the strike of rounds to guide the gunner.The situation with the high-explosive shell was that the 3 inch M42 projectile for the 76 mm gun carried a filler of about of explosives while the 75 mm gun M48 high explosive projectile carried .Far more high explosive ammunition was used by tankers than armor penetrating types, the ratio being about 70% HE, 20% AP and 10% smoke overall, The ratio could vary by unit