| M20 recoilless rifle | |
|---|---|
 An M20recoilless rifle in action during theKorean War | |
| Type | Recoilless anti-tank weapon |
| Place of origin | United States |
| Service history | |
| Used by | United States |
| Wars | |
| Production history | |
| Designed | 1944 |
| Produced | 1945 |
| Variants | Type 56 |
| Specifications | |
| Mass | 103 lb (47 kg) |
| Length | 82 in (2.1 m) |
| Barrel length | 65 in (1.7 m) |
| Crew | 1 or 2[2] |
| Shell | 75 x 408 mm R[3] HE, HEAT, Smoke |
| Shell weight | 20.5–22.6 lb (9.3–10.3 kg) |
| Caliber | 75 mm (3.0 in) |
| Recoil | Recoilless |
| Carriage | M1917A1 tripod |
| Elevation | −27° to +65° |
| Traverse | 360°[2] |
| Muzzle velocity | 1,000 ft/s (300 m/s) |
| Maximum firing range | 3.9 mi (6.3 km)[2] |
TheM20 recoilless rifle is a U.S. 75 mm caliberrecoilless rifle that was used during the last months of theSecond World War and extensively during theKorean War. It could be fired from anM1917A1 .30 caliber machine gun tripod, or from a vehicle mount, typically aJeep. Itsshaped charge warhead, also known asHEAT, was capable of penetrating 100 mm of armor. Although the weapon proved ineffective against theT-34 tank and most other tanks during theKorean War, it was used primarily as a close infantry support weapon to engage all types of targets including infantry and lightly armored vehicles. The M20 proved useful againstpillboxes and other types of field fortifications.
DuringWorld War II, the U.S. military recognized that, due to advancements in armor technology by enemy forces, a powerful lightweight weapon was needed to defend infantry and light armor units. The Ordnance Department Small Arms Division commenced development of a recoilless rifle and, by 1944, models of a 75 mm recoilless rifle were being tested. Production of the M20 was underway by March 1945; only limited numbers were used by Allied troops in the European and Pacific theaters.
The M20 relied on a perforated artillery shell casing, combined with a rear vented breech using propellant gases from the firing of a shell, to greatly reduce the recoil of the weapon. It is this use of vented propellant gases that eliminated the need for a recoil system, thereby reducing the weight of the launcher and enhancing its use as a light infantry weapon.
The M20 was one of the main anti-tank weapons used by the U.S. military in the early days of theKorean War along with the 2.36-inchbazooka. However, the recoilless rifle failed to destroy any North Korean T-34-85 during theBattle of Osan on July 5, 1950. After the deployment of the 3.5-inch M20 Super Bazooka in mid-July, the M20 recoilless rifle no longer functioned as an anti-tank weapon, and was used as an infantry support weapon. It was a very effective weapon to destroy enemy bunkers and trenches with easy transportation benefitted from light weight while providing great firepower.[4]
Recoilless rifles, such as the M20, were also used successfully in large numbers by both sides in theFirst Indochina War (1946–54). They were phased out after being replaced by wire guided missiles, which were introduced during theVietnam War in the 1960s and 1970s. Until stockpiles of ammunition were exhausted in the 1990s, M20 recoilless rifles were used to start controlledavalanches by the U.S.National Forest Service andNational Park Service.[5]
TheRoyal Moroccan Army used M20s during theWestern Sahara War against thePolisario Front.[6]
China also produced unlicensed copies, known as theType 52 andType 56 (an upgraded version that could fire fin-stabilized HEAT shells). These versions were widely used by theNorth Vietnamese Army (NVA) andVietcong guerrillas in the Vietnam War[7] and there are also pictures suggesting its use byguerrillas and militias in theLebanese Civil War (1975–1990), such as theAmal Movement militia.[8]
Albania: Type 56[9]
Argentina: M20[10]
Brazil: M20[10]
Burkina Faso: Type 52[10]
Burundi: Type 52[10]
Cameroon: Type 52[11]
Colombia: M20[10]
Democratic Republic of the Congo: M20[10]
People's Republic of China: Type 52 and Type 56[10]
El Salvador[10]
Ethiopian Empire: M20s were used by theKagnew Battalion[12]
France
Guinea-Bissau: Type 52[10]
Indonesia: Type 52 and Type 56 used byIndonesian Marine Corps[13]
Lebanon
Mauritania: M20[10]
Myanmar:Both US M-20 and Chinese Type 52 and Type 56[citation needed]
Netherlands[14]
Niger: M20[10]
Pakistan: Type 52[10]
Paraguay: M20[10]
Philippines: M20[10]
Portugal: M20
Saudi Arabia: M20[10]
South Korea: TheArmed Forces began receiving M20s from the U.S. in 1951, and 601 were in service with theArmy by the end of theKorean War.[4]
Tanzania: Type 52[10]
Togo: Type 56[10]
United States
Vietnam: Type 52 and Type 56[10]
South Vietnam: M20[15]
Turkey: M20[16] 617 units.
Yemen: M20[10]
Yugoslavia: M20[10]
Zambia: M20[10]{{cite web}}: CS1 maint: numeric names: authors list (link)