The M10 tank destroyer was an American tank destroyer of World War II. After US entry into World War II and the formation of the Tank Destroyer Force, a suitable vehicle was needed to equip the new battalions. By November 1941, the Army requested a vehicle with a gun in a fully rotating turret after other interim models were criticized for being too poorly designed. The prototype of the M10 was conceived in early 1942, being delivered in April of that year. After appropriate changes to the hull and turret were made, the modified version was selected for production in June 1942 as the 3-inch Gun Motor Carriage M10. It mounted a 3-inch (76.2 mm) gun M7 in a rotating turret on a modified M4A2 Sherman tank chassis. An alternate model, the M10A1, which used the chassis of an M4A3 Sherman tank, was also produced. Production of the two models ran from September 1942 to December 1943 and October 1942 to November 1943, respectively.
A total of 1,648 M10s were supplied by the United States to the British Army via the Lend-Lease program. British M10s were designated as 3in SPM M10. The M10 with the "wedge" counterweight was known as the 3in SPM M10 Mk I and the M10 with the "duck bill" counterweight was designated the 3in SPM M10 Mk II. 1,017 of the vehicles were up-gunned with the powerful 17-pounder gun from May 1944 to April 1945. A nickname used within the Department of Tank Design for both the 3-inch and 17-pounder versions was "Achilles"; the name was not used by troops during the war.