M18 recoilless rifle
Encyclopedia
The M18 recoilless rifle was a 57 mm shoulder fired anti-tank recoilless rifle
used by the U.S. Army in World War II
and the Korean War
. Recoilless rifles are capable of firing artillery
-type shells at reduced velocities comparable to those of standard cannon, but with greater accuracy than anti-tank
weapons that used unguided rockets, and almost entirely without recoil
. The M18 was a breech-loaded, single-shot, man-portable, crew-served weapon. It could be used in both anti-tank and anti-personnel
roles. The weapon could be both shoulder fired or stabilised using a monopod
. The most stable firing position was from the tripod developed for the water-cooled Browning M1917 machine gun.
, based on captured German models
that used a plastic blow out plug in the cartridge case. At the same time, there was a freelance research by the U.S. Army's Infantry Section of a man-portable recoilless 57 mm cannon by two engineers, named Kroger and Musser. Instead of a blowout plug, the infantry section's recoilless cannon used a British development in which the cartridge case had hundreds of small holes in the side walls with a lining of plastic on the inside of the cartridge case walls to keep water and other elements out until the round was fired. Another unique innovation was the use of pre-engraving bands on the 57 mm projectile that engaged the barrel's rifling. The belief was this feature would reduce friction on firing, allowing more of the propellant gases to be used to force the shell towards the target and less being used to achieve the recoilless effect and therefore giving their design a much higher muzzle velocity than most recoilless cannon at that time period had achieved.
The "Kromuskit", as the new 57 mm weapon was called (a word play on the engineers' family names) was officially designated the T15 and first tested in November 1943. The tests proved that the Infantry Section's concept for a recoilless weapon was superior to the Artillery Section's concept and the development of the 105 mm weapon was canceled. In late 1944, the T15 was redesignated the M18 57 mm Recoilless. The cannon and 57 mm ammunition were placed in mass production. Four types of ammunition were initially produced: an anti-tank HEAT
round, an HE round, a smoke shell using white phosphorus, and a training round. By early 1945, over 2,000 M18 recoilless rifles and 800,000 rounds of ammunition were on order.
in March 1945. Further examples were subsequently sent to the Pacific Theater
. The first combat the new cannon saw was with the U.S. Army's 17th Airborne Division near Essen, Germany. While impressed with the performance of the high explosive (HE) warhead, the M18's 57 mm HEAT anti-tank round proved to be a disappointment, with only 63.5 mm (2.5-in.) of armor penetration
at 90 degrees, compared with the older M1A1 Bazooka
which had a nominal penetration of nearly 120 mm.
In the Pacific Theater, the new lightweight 57 mm cannon was an absolute success as "pocket artillery" for the soldiers of U.S. Army infantry units that were issued the M18. It was first used in the Pacific Theater during the Battle of Okinawa
on June 9, 1945, and proved with its HE and WP rounds it was the perfect weapon for the hard fighting that took place against the dug-in Japanese
in the hills of that island. The only complaint the U.S. Army had was the lack of sufficient 57 mm ammunition for the M18.
have mentioned the use of the M18 against enemy machine gun nests. For anti-tank tasks, however, the M18 was too weak; the T-34
tank was extremely hard to penetrate even for the 2.36 inch (60 mm) Bazooka of World War II which had almost no chance to penetrate it. The only way would have been flank or rear shots. U.S. infantry, initially with very few capabilities against these targets, solved the problem with new weapons like the 3.5 inch (89 mm) M20 Super Bazooka, which was powerful enough to destroy T-34s.
as the Type 36. The U.S. had provided Nationalist China the blueprints for the weapon. When the communists seized the factory, they took advantage of the facilities and blueprints to make their own copy of the weapon. China provided the Vietnamese communists the Type 36 in 1963 for use in the Vietnam War
. Tanzania
was also a user of the Type 36. In a strange twist, the Chinese version of the M18 can fire both U.S. and Chinese manufactured ammunition, but U.S. made M18s can not fire Chinese ammunition. As late as 1984, the M18 57 mm recoilless rifle was still being produced under license in Brazil by Hydroar in São Paulo
.
Recoilless rifle
A recoilless rifle or recoilless gun is a lightweight weapon that fires a heavier projectile than would be practical to fire from a recoiling weapon of comparable size. Technically, only devices that use a rifled barrel are recoilless rifles. Smoothbore variants are recoilless guns...
used by the U.S. Army in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
and the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
. Recoilless rifles are capable of firing artillery
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
-type shells at reduced velocities comparable to those of standard cannon, but with greater accuracy than anti-tank
Anti-tank warfare
Anti-tank warfare was created by the need to seek technology and tactics to destroy tanks and their supporting infantry during the First World War...
weapons that used unguided rockets, and almost entirely without recoil
Recoil
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gasses, according to Newton's third law...
. The M18 was a breech-loaded, single-shot, man-portable, crew-served weapon. It could be used in both anti-tank and anti-personnel
Anti-personnel weapon
An anti-personnel weapon is one primarily used to incapacitate people, as opposed to attacking structures or vehicles.The development of defensive fortification and combat vehicles gave rise to weapons designed specifically to attack them, and thus a need to distinguish between those systems and...
roles. The weapon could be both shoulder fired or stabilised using a monopod
Monopod
A monopod, also called a unipod, is a single staff or pole used to help support cameras, video cameras, binoculars, rifles or other precision instruments in the field.-Camera and imaging use:...
. The most stable firing position was from the tripod developed for the water-cooled Browning M1917 machine gun.
Origins and development
During World War II, the U.S. Army's Artillery Section was working on a 105 mm recoilless cannonRecoilless rifle
A recoilless rifle or recoilless gun is a lightweight weapon that fires a heavier projectile than would be practical to fire from a recoiling weapon of comparable size. Technically, only devices that use a rifled barrel are recoilless rifles. Smoothbore variants are recoilless guns...
, based on captured German models
10.5 cm Leichtgeschütz 40
The 10.5 cm Leichgeschütz 40, also called the LG 40, was a German recoilless gun used during World War II. It was manufactured by Krupp.-History:...
that used a plastic blow out plug in the cartridge case. At the same time, there was a freelance research by the U.S. Army's Infantry Section of a man-portable recoilless 57 mm cannon by two engineers, named Kroger and Musser. Instead of a blowout plug, the infantry section's recoilless cannon used a British development in which the cartridge case had hundreds of small holes in the side walls with a lining of plastic on the inside of the cartridge case walls to keep water and other elements out until the round was fired. Another unique innovation was the use of pre-engraving bands on the 57 mm projectile that engaged the barrel's rifling. The belief was this feature would reduce friction on firing, allowing more of the propellant gases to be used to force the shell towards the target and less being used to achieve the recoilless effect and therefore giving their design a much higher muzzle velocity than most recoilless cannon at that time period had achieved.
The "Kromuskit", as the new 57 mm weapon was called (a word play on the engineers' family names) was officially designated the T15 and first tested in November 1943. The tests proved that the Infantry Section's concept for a recoilless weapon was superior to the Artillery Section's concept and the development of the 105 mm weapon was canceled. In late 1944, the T15 was redesignated the M18 57 mm Recoilless. The cannon and 57 mm ammunition were placed in mass production. Four types of ammunition were initially produced: an anti-tank HEAT
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
round, an HE round, a smoke shell using white phosphorus, and a training round. By early 1945, over 2,000 M18 recoilless rifles and 800,000 rounds of ammunition were on order.
World War II
The first fifty production M18 57 mm cannons and ammunition were rushed from the factories to the European TheaterEuropean Theatre of World War II
The European Theatre of World War II was a huge area of heavy fighting across Europe from Germany's invasion of Poland on September 1, 1939 until the end of the war with the German unconditional surrender on May 8, 1945...
in March 1945. Further examples were subsequently sent to the Pacific Theater
Pacific Theater of Operations
The Pacific Theater of Operations was the World War II area of military activity in the Pacific Ocean and the countries bordering it, a geographic scope that reflected the operational and administrative command structures of the American forces during that period...
. The first combat the new cannon saw was with the U.S. Army's 17th Airborne Division near Essen, Germany. While impressed with the performance of the high explosive (HE) warhead, the M18's 57 mm HEAT anti-tank round proved to be a disappointment, with only 63.5 mm (2.5-in.) of armor penetration
Armor-piercing shot and shell
An armor-piercing shell is a type of ammunition designed to penetrate armor. From the 1860s to 1950s, a major application of armor-piercing projectiles was to defeat the thick armor carried on many warships. From the 1920s onwards, armor-piercing weapons were required for anti-tank missions...
at 90 degrees, compared with the older M1A1 Bazooka
Bazooka
Bazooka is the common name for a man-portable recoilless rocket antitank weapon, widely fielded by the U.S. Army. Also referred to as the "Stovepipe", the innovative bazooka was amongst the first-generation of rocket propelled anti-tank weapons used in infantry combat...
which had a nominal penetration of nearly 120 mm.
In the Pacific Theater, the new lightweight 57 mm cannon was an absolute success as "pocket artillery" for the soldiers of U.S. Army infantry units that were issued the M18. It was first used in the Pacific Theater during the Battle of Okinawa
Battle of Okinawa
The Battle of Okinawa, codenamed Operation Iceberg, was fought on the Ryukyu Islands of Okinawa and was the largest amphibious assault in the Pacific War of World War II. The 82-day-long battle lasted from early April until mid-June 1945...
on June 9, 1945, and proved with its HE and WP rounds it was the perfect weapon for the hard fighting that took place against the dug-in Japanese
Imperial Japanese Army
-Foundation:During the Meiji Restoration, the military forces loyal to the Emperor were samurai drawn primarily from the loyalist feudal domains of Satsuma and Chōshū...
in the hills of that island. The only complaint the U.S. Army had was the lack of sufficient 57 mm ammunition for the M18.
Korean War
Each U.S. rifle company in the Korean War was authorized three M18 recoilless rifles. Veterans of the Korean WarKorean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
have mentioned the use of the M18 against enemy machine gun nests. For anti-tank tasks, however, the M18 was too weak; the T-34
T-34
The T-34 was a Soviet medium tank produced from 1940 to 1958. Although its armour and armament were surpassed by later tanks of the era, it has been often credited as the most effective, efficient and influential design of World War II...
tank was extremely hard to penetrate even for the 2.36 inch (60 mm) Bazooka of World War II which had almost no chance to penetrate it. The only way would have been flank or rear shots. U.S. infantry, initially with very few capabilities against these targets, solved the problem with new weapons like the 3.5 inch (89 mm) M20 Super Bazooka, which was powerful enough to destroy T-34s.
Production and use outside the US
The M18 was copied by the People's Republic of ChinaPeople's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
as the Type 36. The U.S. had provided Nationalist China the blueprints for the weapon. When the communists seized the factory, they took advantage of the facilities and blueprints to make their own copy of the weapon. China provided the Vietnamese communists the Type 36 in 1963 for use in the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
. Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
was also a user of the Type 36. In a strange twist, the Chinese version of the M18 can fire both U.S. and Chinese manufactured ammunition, but U.S. made M18s can not fire Chinese ammunition. As late as 1984, the M18 57 mm recoilless rifle was still being produced under license in Brazil by Hydroar in São Paulo
São Paulo
São Paulo is the largest city in Brazil, the largest city in the southern hemisphere and South America, and the world's seventh largest city by population. The metropolis is anchor to the São Paulo metropolitan area, ranked as the second-most populous metropolitan area in the Americas and among...
.
External links
- U.S. 57mm Recoilless Rifle at Inert-Ord.net
- New Kickless Cannon for GIs Popular Science 1945