M40 recoilless rifle
Encyclopedia
The M40 recoilless rifle
was a lightweight, portable, crew-served 105 mm weapon intended primarily as an anti-tank weapon
made in the United States
. The weapon is commonly described as being 106 mm, but it is in fact 105 mm; the 106 mm designation was designed to prevent confusion with the incompatible 105 mm ammunition from the failed M27.
It could also be employed in an antipersonnel role with the use of the antipersonnel-tracer flechette round. It can be fired primarily from a wheeled ground mount. The air-cooled, breech-loaded, single-shot
rifle
fired fixed ammunition
. It was designed for direct firing only, and sight
ing equipment for this purpose was furnished with each weapon.
The M27 recoilless rifle was a 105-mm weapon developed in the early 1950s and fielded in the Korean War
. Although a recoilless rifle of this caliber had been a concept since the Second World War, the weapon was hurriedly produced with the onset of the Korean War. The speed with which it was developed and fielded resulted in problems with reliability caused by trunnions that were mounted too far to the rear. The M27 was also considered too heavy by the U.S. Army and had a disappointing effective range due to the lack of a spotting rifle
. Taking the M27 as a the basis for a new design, the Army developed an improved version of the M27 that was type-designated the M40 106-mm recoilless rifle. Although unsuitable for military purposes, M27 recoilless rifles were used to trigger controlled avalanches at ski resorts and mountain passes in the United States.
The M40 primarily saw action during the Vietnam War
and was later replaced by the BGM-71 TOW
anti-tank missile system. The weapon was also used by anti-communist forces in Angola
mounted on Land Rover
s. The type has seen extensive service in the 2011 Libyan Civil War
. The rebel forces, lacking modern artillery, have employed the M40 as both a direct fire and indirect fire weapon.
, but the front leg has a castoring wheel. On top of the mount is a traverse wheel. On the centre of the traverse wheel is a locking wheel, when the wheel is down, the rifle is locked in traverse, and can only be moved right and left with the traverse wheel. When the wheel is raised, the rifle can be traversed by hand. Austria
produced a two-wheeled mount for the M40.
The whole mounting can be placed on an M151
Jeep
for mobile use. It has also been mounted on Land Rover Defenders
, M113
s, Mercedes-Benz G-Wagen
, HMMWVs, Toyota Land Cruiser
s, AIL Storm
s and M274 Mechanical Mules
. They were also used on US Navy Minesweepers (MSO
) during operation Market Time in Viet Nam.
A special vehicle called Ontos
carried six M40s. A version specific to the T195E5 mount, the M40A1C, was used. It was used only by the U.S. Marine Corps. Japan
produced a self propelled gun called the Type 60
which carried two side by side. Some Pakistan
i M113s have a dual mounting.
The M40 was a very successful export item and continues to be used by South Korea
(ROK), Ecuador
, Egypt
, Estonia
, Greece
, Honduras
, Iran
, Israel
, Lebanon
, Malaysia, Mexico
, Morocco
, the Philippines
, Taiwan
(Republic of China Marine Corps
), Turkey
, Colombia
, Cambodia
, Vietnam
, Venezuela
and many others.
It is manufactured in Iran by Defense Industries Organization
as the ANTI-TANK GUN 106.
and the cartridge case. It also permits faster loading because the projectile and the cartridge case are loaded as one unit. The rear end of the cartridge case is perforated, to allow the propellant gas to escape through the vented breech, thus neutralizing recoil. The projectiles used are pre-engraved, that is, the rotating bands are cut to engage the rifled bore.
Types of ammunition included HEAT
, High Explosive Plastic-Tracer
(HEP-T
), canister
, High Explosive Anti Personnel, and the M368 dummy round which could not be fired and was used for crew drill. The original U.S. HEAT round penetrated more than 400 mm of armor. Near the end of the M40's service life, both Austria and Sweden produced HEAT rounds for the weapon capable of penetrating more than 700 mm of armor.
The ammunition for the 0.50 cal spotting rifle is not .50 BMG
. The round used is a special round designed to simulate the flight path of the 105 mm ammunition.
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...
was a lightweight, portable, crew-served 105 mm weapon intended primarily as an anti-tank weapon
Weapon
A weapon, arm, or armament is a tool or instrument used with the aim of causing damage or harm to living beings or artificial structures or systems...
made in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The weapon is commonly described as being 106 mm, but it is in fact 105 mm; the 106 mm designation was designed to prevent confusion with the incompatible 105 mm ammunition from the failed M27.
It could also be employed in an antipersonnel role with the use of the antipersonnel-tracer flechette round. It can be fired primarily from a wheeled ground mount. The air-cooled, breech-loaded, single-shot
Single-shot
Single-shot firearms are firearms that hold only a single round of ammunition, and must be reloaded after each shot. The history of firearms began with single-shot designs, and many centuries passed before multi-shot designs became commonplace...
rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
fired fixed ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
. It was designed for direct firing only, and sight
Sight (device)
A sight is a device used to assist aligning or aim weapons, surveying instruments, or other items by eye. Sights can be a simple set or system of markers that have to be aligned together as well as aligned with the target...
ing equipment for this purpose was furnished with each weapon.
The M27 recoilless rifle was a 105-mm weapon developed in the early 1950s and fielded in 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...
. Although a recoilless rifle of this caliber had been a concept since the Second World War, the weapon was hurriedly produced with the onset of the Korean War. The speed with which it was developed and fielded resulted in problems with reliability caused by trunnions that were mounted too far to the rear. The M27 was also considered too heavy by the U.S. Army and had a disappointing effective range due to the lack of a spotting rifle
Spotting rifle
A spotting rifle is a small-calibre rifle used as a sighting device for artillery. The ballistics of the spotting rifle are matched to those of the artillery piece, so that if a shot from the spotting rifle lands on the target, it may be assumed that the main weapon will also do so.- Anti-tank...
. Taking the M27 as a the basis for a new design, the Army developed an improved version of the M27 that was type-designated the M40 106-mm recoilless rifle. Although unsuitable for military purposes, M27 recoilless rifles were used to trigger controlled avalanches at ski resorts and mountain passes in the United States.
The M40 primarily saw action during 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...
and was later replaced by the BGM-71 TOW
BGM-71 TOW
The BGM-71 TOW is an anti-tank missile. "BGM" is a weapon classification that stands for "Multiple Environment , Surface-Attack , Missile ". "TOW" is an acronym that stands for "Tube-launched, Optically-tracked, Wire command data link, guided missile"...
anti-tank missile system. The weapon was also used by anti-communist forces in Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...
mounted on Land Rover
Land Rover
Land Rover is a British car manufacturer with its headquarters in Gaydon, Warwickshire, United Kingdom which specialises in four-wheel-drive vehicles. It is owned by the Indian company Tata Motors, forming part of their Jaguar Land Rover group...
s. The type has seen extensive service in the 2011 Libyan Civil War
2011 Libyan civil war
The 2011 Libyan civil war was an armed conflict in the North African state of Libya, fought between forces loyal to Colonel Muammar Gaddafi and those seeking to oust his government. The war was preceded by protests in Benghazi beginning on 15 February 2011, which led to clashes with security...
. The rebel forces, lacking modern artillery, have employed the M40 as both a direct fire and indirect fire weapon.
Description
The M40 is shaped like a long tube with a M8 0.50 cal spotting rifle above. The spotting rifle fires a round that flies like the 106 mm round and gives off a puff of smoke on impact with the target. On the left hand side, there is an elevating wheel, in the centre of which is the trigger wheel used to fine adjust the elevation and at the same time firing the spotting rifle when pulled, and the gun when pushed. The mounting is a tripodTripod
A tripod is a portable three-legged frame, used as a platform for supporting the weight and maintaining the stability of some other object. The word comes from the Greek tripous, meaning "three feet". A tripod provides stability against downward forces, horizontal forces and moments about the...
, but the front leg has a castoring wheel. On top of the mount is a traverse wheel. On the centre of the traverse wheel is a locking wheel, when the wheel is down, the rifle is locked in traverse, and can only be moved right and left with the traverse wheel. When the wheel is raised, the rifle can be traversed by hand. Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
produced a two-wheeled mount for the M40.
The whole mounting can be placed on an M151
M151
The M151 MUTT was the successor to the Korean War M38 and M38A1 jeep Light Utility Vehicles. It was produced from 1959 through 1982 and served in the Vietnam War. The M151 utilized a monocoque design making it roomier than previous jeep designs, and incorporated an independent suspension with coil...
Jeep
Jeep
Jeep is an automobile marque of Chrysler . The first Willys Jeeps were produced in 1941 with the first civilian models in 1945, making it the oldest off-road vehicle and sport utility vehicle brand. It inspired a number of other light utility vehicles, such as the Land Rover which is the second...
for mobile use. It has also been mounted on Land Rover Defenders
Land Rover (Series/Defender)
The Land Rover Defender is a British four wheel drive off-road utility vehicle developed from the original Land Rover Series launched in 1948.-Name and badge distinctions:...
, M113
M113 Armored Personnel Carrier
The M113 is a fully tracked armored personnel carrier that has formed the backbone of the United States Army's mechanized infantry units from the time of its first fielding in Vietnam in April 1962. The M113 was the most widely used armored vehicle of the U.S...
s, Mercedes-Benz G-Wagen
Mercedes-Benz G-Class
The original 460-series Geländewagen went on sale for civilian buyers in 1979, after having debuted in February of that year. It was offered with two wheelbases, a short wheelbase of 2,400 mm and a long one of 2,850 mm. One could choose between three body styles: A two-door short...
, HMMWVs, Toyota Land Cruiser
Toyota Land Cruiser
The is a series of four-wheel drive vehicles produced by the Japanese car maker Toyota Motor Corporation. It is not related to the Studebaker Land Cruiser car produced in the US from 1934-1954....
s, AIL Storm
AIL Storm
The AIL Storm is an Israeli manufactured off-road vehicle and the workhorse of the Israeli Security Forces. The series of Jeep Wrangler based vehicles have been produced by Automotive Industries Ltd. in Upper Nazareth under licence from Chrysler since 1990...
s and M274 Mechanical Mules
U.S. Military M274 Truck, Platform, Utility 1/2 Ton, 4X4
The U.S. Military M274 Truck, Platform, Utility 1/2 Ton, 4X4 or "Carrier, Light Weapons, Infantry, 1/2 ton, 4x4" aka "Mule," "Military Mule," or "Mechanical Mule" is a 4-wheel drive, gas-powered truck/tractor type vehicle that can carry up to a 1/2 ton off-road. It was introduced in 1956 and used...
. They were also used on US Navy Minesweepers (MSO
MSO
MSO is an abbreviation that may stand for:Orchestras* Madison Symphony Orchestra, of Madison, Wisconsin, USA* Melbourne Symphony Orchestra, of Melbourne, Victoria, Australia* Metropolitan Symphony Orchestra, of Minneapolis, Minnesota, USA...
) during operation Market Time in Viet Nam.
A special vehicle called Ontos
Ontos
The Ontos, officially the Rifle, Multiple 106 mm, Self-propelled, M50, was an American light armored tracked anti-tank vehicle developed in the 1950s...
carried six M40s. A version specific to the T195E5 mount, the M40A1C, was used. It was used only by the U.S. Marine Corps. Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
produced a self propelled gun called the Type 60
Type 60 Self-propelled 106 mm Recoilless Gun
The is a light anti-tank vehicle developed by Japan in the late 1950s. It mounts two M40 106 mm recoilless rifles as its main armament.- Development :...
which carried two side by side. Some Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
i M113s have a dual mounting.
The M40 was a very successful export item and continues to be used by South Korea
South Korea
The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...
(ROK), Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
, Estonia
Estonia
Estonia , officially the Republic of Estonia , is a state in the Baltic region of Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by Lake Peipsi and the Russian Federation . Across the Baltic Sea lies...
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
, Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
, Lebanon
Lebanon
Lebanon , officially the Republic of LebanonRepublic of Lebanon is the most common term used by Lebanese government agencies. The term Lebanese Republic, a literal translation of the official Arabic and French names that is not used in today's world. Arabic is the most common language spoken among...
, Malaysia, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
, the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
(Republic of China Marine Corps
Republic of China Marine Corps
Republic of China Marine CorpsPersonnel15,000 The Republic of China Marine Corps is the amphibious arm of the Republic of China Navy responsible for amphibious combat, counter-landing and reinforcement of the main island of Taiwan, remote islands, defense of ROCN facilities, and also functions as...
), Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
, Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
, Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
and many others.
It is manufactured in Iran by Defense Industries Organization
Defense Industries Organization
The Defense Industries Organization The Defense Industries Organization The Defense Industries Organization (DIO; Persian: Sasadjah (Sazemane Sanaye Defa) is a conglomerate of companies run by the Islamic Republic of Iran whose function is to provide the military of Iran with the necessary...
as the ANTI-TANK GUN 106.
Ammunition
Ammunition for the 105 mm rifle was issued as one-piece fixed cartridges. The term "fixed" means that the projectile and the cartridge case are crimped together. This ensures correct alignment of the projectileProjectile
A projectile is any object projected into space by the exertion of a force. Although a thrown baseball is technically a projectile too, the term more commonly refers to a weapon....
and the cartridge case. It also permits faster loading because the projectile and the cartridge case are loaded as one unit. The rear end of the cartridge case is perforated, to allow the propellant gas to escape through the vented breech, thus neutralizing recoil. The projectiles used are pre-engraved, that is, the rotating bands are cut to engage the rifled bore.
Types of ammunition included 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...
, High Explosive Plastic-Tracer
Tracer
Tracer may refer to:* Histochemical tracer, a substance used for tracing purposes in histochemistry, the study of the composition of cells and tissues...
(HEP-T
High explosive squash head
High explosive squash head is a type of explosive ammunition that is effective against buildings and is also used against tank armour. It was fielded chiefly by the British Army as the main explosive round of its main battle tanks during the Cold War...
), canister
Canister shot
Canister shot is a kind of anti-personnel ammunition used in cannons. It was similar to the naval grapeshot, but fired smaller and more numerous balls, which did not have to punch through the wooden hull of a ship...
, High Explosive Anti Personnel, and the M368 dummy round which could not be fired and was used for crew drill. The original U.S. HEAT round penetrated more than 400 mm of armor. Near the end of the M40's service life, both Austria and Sweden produced HEAT rounds for the weapon capable of penetrating more than 700 mm of armor.
| Producer | Round name |
Type | Proj Weight |
Proj Filler |
Filler weight |
Armour penetration |
Effective range |
|---|---|---|---|---|---|---|---|
 |
M581 | APERS | 9.89 kg | flechette Flechette A flechette is a pointed steel projectile, with a vaned tail for stable flight. The name comes from French , "little arrow" or "dart", and sometimes retains the acute accent in English: fléchette.-Bulk and artillery use:... s |
4.94 kg | N/A | 300 m |
 |
M-DN11 | HEAP | 3.6 kg | Hexogen | 0.77 kg | N/A | 1500 m |
 |
NR 160 | HEAT-T | N/A | N/A | N/A | N/A | N/A |
| |
NR 483 | APERS | N/A | flechette Flechette A flechette is a pointed steel projectile, with a vaned tail for stable flight. The name comes from French , "little arrow" or "dart", and sometimes retains the acute accent in English: fléchette.-Bulk and artillery use:... s |
N/A | N/A | N/A |
| |
NR 601 | HESH-T | 7.8 kg | Comp. A3 | N/A | N/A | N/A |
 |
PFF | HE | 9.89 kg | Comp. B Composition B Composition B, colloquially "comp B", is an explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades, sticky bombs and various other munitions... |
N/A | N/A | N/A |
| |
M346A1 | HEP-T | 7.96 kg | Comp. A3 | 3.5 kg | N/A | N/A |
| |
M344A1 | HEAT | 7.96 kg | Comp. B | 1.27 kg | over 400 mm | 1350 m |
 |
106 3A | HEAT-T | 5.5 kg | Octol Octol Octol is a melt-castable, high explosive mixture consisting of HMX and TNT in different weight proportions.-Composition:Two formulations are commonly used:* 70% HMX & 30% TNT* 75% HMX & 25% TNT... |
1.0 kg | over 700 mm | 2000 m |
 |
RAT 700 | HEAT | 5.0 kg | N/A | 1.1 kg | over 700 mm | N/A |
The ammunition for the 0.50 cal spotting rifle is not .50 BMG
.50 BMG
The .50 Browning Machine Gun or 12.7×99mm NATO is a cartridge developed for the Browning .50 caliber machine gun in the late 1910s. Entering service officially in 1921, the round is based on a greatly scaled-up .30-06 cartridge...
. The round used is a special round designed to simulate the flight path of the 105 mm ammunition.