M10 Tank Destroyer - Armament

Armament

The M10 used a Medium Tank M4A2 chassis (M10A1s used M4A3 chassis) with an open-topped turret mounting a 3" gun M7. This gun fired the Armor Piercing M79 shot that could penetrate 3 inches of armor at 1,000 yards at 30 degrees from vertical. Other ammunition carried throughout its service life included the Armor Piercing Capped Ballistic Cap (APCBC) M62 projectile, High Velocity Armor Piercing (HVAP) M93 shot, and Armor Piercing High Explosive (APHE); 54 rounds of 3-inch ammunition were carried. The rear of the turret carried two large counterweights which gave it a distinctive shape. The main shortcoming of the M-10'x 3 inch cannon was its APHE round, which was the round most commonly used for engaging tanks. The 3 inch APHE round was based on the naval 3 inch round and had a small charge in the rear of the round which was supposed to explode after penetration of the targeted tank's armor plating. Unfortunately it was discovered that it exploded on impact or shortly thereafter, causing the round not to penetrate. It is still a puzzling mystery as to why this problem was never addressed with a better base fuse or by deleting the small HE charge in the rear of the round. This was also the problem with the towed version of the 3 inch cannon, the M-5, in the antitank role.

A .50-caliber Browning M2HB machine gun could be mounted on the top rear of the turret for use against enemy infantry and for anti-aircraft use, along with 1000 rounds. The crew were also equipped with their personal weapons for self-protection.