, June 1944. advances along a mountain road in Italy, 3 March 1945. ===
United States Army=== during
World War II. The M10's heavy chassis did not conform to the quickly evolving tank destroyer doctrine of employing very light high-speed vehicles, and starting in the summer of 1944 it began to be supplemented by the fast
M18 Hellcat. American tank destroyer doctrine called for tank destroyers to be kept in reserve and rushed forward to counter massed enemy armored attacks. In reality, this was not the case and M10 battalions were attached, often semi-permanently, to infantry and armored divisions to provide additional direct and indirect fire support. Typical missions included providing indirect artillery fire by augmenting divisional artillery units, following and supporting the lead elements of an infantry assault, attacking obstacles such as fortifications and enemy vehicles (including tanks) that hampered the advance of friendly units, and setting up an antitank defense once the objective was secured. The combat debut of the M10 came on 23 March 1943, during the
Battle of El Guettar, in the
Tunisian campaign part of the larger
North African campaign. The M10 was initially successful as its M7 3-inch gun could destroy most German tanks then in service. During the battle, M10s of the 899th Tank Destroyer Battalion and
M3 Gun Motor Carriages of the
601st Tank Destroyer Battalion destroyed 30 German tanks, although 20 M3s and 7 M10s were lost. The M10 did not see much anti-tank action for the rest of the North African campaign, and instead was used as mobile fire support. During tank fighting in the
Normandy campaign, the M10's 3-inch gun was proven to be ineffective against the thick frontal armor of the German
Panther medium tank. On 6 July 1944,
Eisenhower's headquarters requested that all M10 battalions be converted to the new
M36 as soon as possible. On 10 July 1944, the
899th Tank Destroyer Battalion blunted a German counterattack by the
Panzer Lehr Division near
Le Dézert and destroyed 12 Panthers, one
Panzer IV, and one
Sturmgeschütz III assault gun in a fierce two-day battle, most of it taking place at ranges of less than . Due to the initial shock of encountering heavy German tanks, further changes were made in the tank destroyer force in late September 1944. American officials requested that of the 52 battalions then committed to the European theater, 20 be converted to the M36, 20 retain the M10 or
M18 at the discretion of their commanders, and the 12 towed battalions be re-equipped with the (then-prototype) T5 90 mm towed gun. By October 1944, the improved 90 mm Gun Motor Carriage M36 began to arrive in Europe, and mostly replaced the M10 by the end of the war. The plans to retain any towed battalions at all were canceled after their generally poor performance and high losses in 1944, especially during the
Battle of the Bulge. In the Italian campaign, as in northern Europe, the M10s were normally attached to infantry or armored units as infantry support or mobile artillery, more so the latter because of the general lack of German armor in that theater. Many US divisional commanders asked for their M10s to be replaced with fully armored tanks. In the
Pacific war, due to the lack of serious Japanese tank opposition, US Army M10s were not used as tank destroyers, but as mobile artillery and infantry support. The M10 proved unpopular in the Pacific due to its open turret, which left it vulnerable to Japanese close-assault antitank tactics. ===
British Army=== The United States supplied 1,648 M10s to the British Army via the Lend-Lease program. The British gave them the designation
3inch Self-propelled Mount M10 (3-in 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 the "3in SPM M10 Mk II". 1,017 of the vehicles were up-gunned with the powerful
17-pounder (76.2mm) gun from May 1944 to April 1945. Within the Department of Tank Design both the 3-inch and 17-pounder versions were known as "Achilles". The 17-pounder conversions were designated with a "C" suffix added on to the "M10" designation, called "17pdr M10" or "Achilles Ic". Most of the vehicles converted were the 3in SPM M10 Mk II, as the duck bill counterweight balanced the heavy gun better. The gun mantlet needed modification to accept the barrel. Although the 17-pounder was a similar bore to the 3-inch gun M7, it had a longer barrel and used a larger propellant charge giving far superior armor penetrating capabilities. Using the APDS round, the gun performance was increased by about 50%. The 17pdr SP was used by the British, Canadian and Polish armies in Italy and northwest Europe. As well as service with British forces in Northwest Europe, they were retained post-war. Those not upgunned were stripped of their turrets and used as artillery tractors. In British service, as self-propelled anti-tank guns, the M10 was operated by regiments of the
Royal Artillery. Typically, two batteries had M10s while the other two batteries had the towed 17-pounder gun. One tactical theory was that the two towed batteries would form a gun line, while an M10 battery remained mobile on each flank to drive or lead enemy tanks to the static gun line. In practice, UK batteries were frequently separated in Normandy, M10s being seconded to British
tank brigades equipped with
Churchill tanks armed with the
general purpose 75 mm gun just as were British 17 pounder conversions. ===
Free French Army=== The Free French received at least 227 M10s, 155 of them through Lend-Lease. They served first in Italy, then in France and Germany. During the
liberation of Paris in August 1944, a single M10 of General Leclerc's
2nd Armored Division named "Siroco" disabled a Panther in the
Place de la Concorde from under the
Arc de Triomphe on the
''Place de L'Etoile'', at 1,800 m. French M10s also saw action on the French-German border around
Strasbourg and in southern Germany; the Free French
First Army led by General De Lattre received some when they were a part of the
Sixth United States Army Group. French M10s were operated along similar lines as US tank destroyer units, although initially with five vehicles per platoon instead of four. ===
Red Army=== Approximately 52 M10s were supplied to the
Soviet Union through Lend-Lease. They were used to form two self-propelled artillery regiments (SPA). The first was the 1223rd Self-propelled Artillery Regiment of the
29th Tank Corps, part of the
5th Guards Tank Army. This unit served on the
3rd Belorussian Front in 1944, taking part in summer campaigns in Belorussia, the Baltic, and East Prussia. The 1239th Self-propelled Artillery Regiment was part of the
16th Tank Corps, 2nd Tank Army. It fought in Belorussia and Poland in 1944. ===
Israel=== Israel bought M10s from scrapyards and dumping grounds in Europe after 1948. They had the idea to up-gun the M10 with the modern SA50 gun, which was considered an improvement. The first batch arrived in 1951 and were in very bad shape. Some years later, as the M10's guns were worn out, Israel decided to install 17-pounder guns and also French high-velocity 75 mm CN 75-50 guns that had just been bought. These were called the M50 Achilles. Israel requested the assistance of France to develop the new tank in 1953. After building the prototype, France taught Israel how to do it themselves and provided their technical knowledge related to this development along with a contract to sell the SA50 guns and ammunition. The M10s were repaired and entered service in 1955. Israel captured Egyptian Sherman tanks that had diesel engines during the
1956 war and installed the engines in M10s. They were withdrawn from service by 1966. ===
Egypt=== The Egyptian Army had a small number of ex-British M10s, 3-inch and 17-pdr versions, and used them in the
1948 Arab-Israeli War against Israel. Israel captured some of them. ==Combat performance==