75 mm US tank gun

The US 75 mm gun tank gun M2 and the later M3 were the standard American tank guns of the World War II, used primarily on the two main American medium tanks of the war, the M3 Lee (M2 or M3 gun) and the M4 Sherman (M3 gun).

The lightweight M6 and M5 variants were developed to equip the M24 Chaffee light tank, and the -G and -H subtypes of the B-25 Mitchell bomber respectively. The M3 was also used on the prototype M7 Medium Tank platform.

The 75 mm tank gun has its origins in the famous French Canon de 75 modèle 1897 field gun of World War I fame, which was also adopted by the United States and used well into World War II as the 75 mm M1897 field gun. The tank and field guns fired the same range of 75x350R ammunition. The primary round was the 6.76 kg (14.9 lb) M48 High Explosive round, which travelled at 625 m/s (2,050 ft/s) and contained 1.5 pounds (680g) of TNT filling (2845 kilojoules of explosive energy) and a choice of fuse; the Super Quick (SQ) and the Delay (PD), which had delays of 0.05 and 0.15 seconds respectively. SQ was the standard setting, with PD used against structures, gun positions or lightly protected vehicles. The field gun origins of the ordnance and ammunition ensured that the M2/3/6 series HE round was highly effective for its caliber. The M48 was available in two versions, standard and supercharge, which had an increased propellent charge for greater muzzle velocity (1,885 ft/s (575 m/s) vs. 1,470 ft/s (450 m/s)) and range (2,300 yards greater).

Other important rounds fired by the 75 mm tank guns included the T30 canister shot for use against troops in the open at short range. This, which was essentially a giant shotgun shell full of large numbers of steel balls, was used primarily in the Pacific. There was also the M89 base-ejecting hexachloroethane (HC) smoke round and the M64 white phosphorus (WP or "Willy Pete") round, which proved highly effective in the bocage fighting around Normandy. Finally, there were two different armor-piercing rounds.

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