Infantry Weapons

M40 106 mm recoilless rifle

Also known as
  • M40 recoilless rifle
  • 106mm M40
  • 105 mm M40
  • M40A1
  • M40A1C
  • Anti-Tank Gun 106

The M40 106 mm recoilless rifle is a U.S.-origin crew-served direct-fire weapon built around a 105 mm-class round but commonly identified by its 106 mm designation. It served on ground carriages and vehicle mounts such as the M50 Ontos, remained useful for anti-armor and bunker work after newer missiles appeared, and is documented in conflicts from Vietnam to Libya, Mali, Syria, and Afghanistan.

M40 106 mm recoilless rifle, 106 mm crew-served recoilless rifle, Infantry Weapons
Image source: M274 with M40 in AAFM.jpg

Role in Conflicts

1955 Vietnam War
Fire Support
Side
United States and South Vietnam

U.S. Marine Corps M50 Ontos vehicles carried six M40A1C recoilless rifles in Vietnam; the U.S. Army/RIA account describes the Ontos as shifting into field-support use when enemy armor targets were limited.

1980 Iran-Iraq War
Fire SupportAnti-Armor
Side
Iran

The U.S. Army Center of Military History notes Iranian receipt of M40A1 recoilless rifles for the war against Iraq and identifies the weapon as a direct-fire anti-tank system.

Profile / Specs

Profile

Origin
United States
Type
106 mm crew-served recoilless rifle
Service note
Cold War design; in service from 1955

Specifications

Caliber
105 mm (commonly called 106 mm)
Weight
209.5 kg
Length
3.404 m
Carriage
Tripod or wheeled ground mount
Spotting rifle
12.7 mm M8C spotting rifle used for trajectory-matched ranging before firing the main round
Muzzle velocity
503 m/s with M344 HEAT
Effective range
1,350 m
Maximum range
6,870 m with M346A1 HEP-T
Variants

M40 designations are tied to mount, production, and export context rather than a single clean family tree; the 106 mm label refers to a 105 mm-class weapon kept distinct from incompatible 105 mm ammunition.

VariantConfigurationDesignation notes
M40A1Crew-served recoilless rifle

The U.S. Army Center of Military History describes the M40A1 as a portable, breech-loaded, single-shot recoilless rifle or anti-tank weapon fired primarily from a wheeled ground mount.

Sources: The Relevance of the Army Museum Enterprise

M40A1CM50 Ontos-mounted variant

The U.S. Army/RIA Ontos account identifies the M50 as fitted with six M40A1C recoilless rifles plus an M1919 machine gun.

Sources: RIA Self-Guided Tour: The Ontos

Anti-Tank Gun 106Iranian licensed-origin derivative designation

WIRED reported Iran's Defense Industry Organization offering a licensed-origin M40 derivative under the Anti-Tank Gun 106 name, while treating the exact supply path to Syria as unresolved.

Sources: Ancient U.S. Weapon Makes a Surprise Reappearance in Syria

Carrier Vehicles

The M40 was widely adapted to vehicle and ground mounts; the Al-Jawad page documents one protected turret configuration.

CarrierCarrier typeCarriage evidence
Al-Jawad armored vehicle, 4x4 armored personnel carrier / internal security vehicle, Armored VehiclesAl-Jawad armored vehicleArmored vehicle mount

Small Arms Defense Journal describes a compact turret on top of an Al-Jawad vehicle that accommodates a 106 mm recoilless gun, with firing controlled from inside the armored turret.

Sources: Infantry Support and Anti-tank Weapons in Latin America

Timeline

M40 106 mm recoilless rifle Key Events

  1. M40 enters service

    The M40 replaced the earlier M27 pattern and entered service as a 105 mm-class recoilless rifle usually identified by the 106 mm designation.

    Sources: 106mm M40

  2. M50 Ontos accepted

    The first M50 Ontos vehicles were accepted in 1956; the U.S. Army/RIA account says the Marine Corps ultimately used the 297 vehicles that were built.

    Sources: RIA Self-Guided Tour: The Ontos

  3. Ontos leaves Marine service

    The U.S. Army/RIA account says the Ontos was taken out of service in 1969, with remaining systems largely removed by 1970.

    Sources: RIA Self-Guided Tour: The Ontos

  4. Libyan rebel use reported

    WIRED later reported M40 use by Libyan rebels during urban fighting against tanks and fortified positions.

    Sources: Ancient U.S. Weapon Makes a Surprise Reappearance in Syria

  5. Northern Mali rebel arsenals documented

    Small Arms Survey and Conflict Armament Research documented 106 mm recoilless rifles among rebel-held materiel in northern Mali.

    Sources: Rebel Forces in Northern Mali

  6. Syrian reappearance reported

    WIRED reported M40 recoilless rifles appearing with Syrian rebel forces, with provenance still uncertain.

    Sources: Ancient U.S. Weapon Makes a Surprise Reappearance in Syria

  7. Army museum support for M40A1 testing

    The U.S. Army Center of Military History described museum-system support to tests involving M40A1 recoilless-rifle spotting-rifle components, a reminder that the type remained relevant to weapons-effect research long after U.S. frontline service.

    Sources: The Relevance of the Army Museum Enterprise

Service Pattern

The M40's combat record is split between formal military inventories and later proliferation. Its direct-fire recoilless layout made it adaptable to ground mounts, light vehicles, and armored installations, while later reporting tracks the same family in state and rebel hands.

Vehicle concentration

The M50 Ontos carried six M40A1C recoilless rifles and saw U.S. Marine Corps service in Vietnam.

Mount flexibility

WeaponSystems.net lists tripod or wheeled ground mounts, and Small Arms Defense Journal documents an Al-Jawad turret accepting a 106 mm recoilless gun.

Derivative designation

WIRED describes Iran's Defense Industry Organization offering a licensed-origin M40 derivative as the Anti-Tank Gun 106.

Proliferation cases

WIRED reports Libyan and Syrian rebel appearances, while Small Arms Survey and Conflict Armament Research document 106 mm recoilless rifles in northern Mali rebel materiel.

Sources: 106mm M40; RIA Self-Guided Tour: The Ontos; Infantry Support and Anti-tank Weapons in Latin America; Ancient U.S. Weapon Makes a Surprise Reappearance in Syria; Rebel Forces in Northern Mali.

Media

M40 106 mm recoilless rifle Videos

M40 106 mm recoilless rifle Images

M40 106 mm recoilless rifle, 106 mm crew-served recoilless rifle, Infantry Weapons - view 1
Source: M40 recoilless rifle at Hoi An Museum.jpg
M40 106 mm recoilless rifle, 106 mm crew-served recoilless rifle, Infantry Weapons - view 2
Source: M40 recoilless rifle, Greek infantry, 1997.jpg
Related Weapon Systems
105 mm M1974 FMK-1 recoilless rifle, 105 mm recoilless rifle, Infantry WeaponsInfantry Weapons105 mm M1974 FMK-1 recoilless rifle105 mm recoilless rifleThe 105 mm M1974 FMK-1 is the later standard in Argentina's Czekalski recoilless-rifle family, a heavy smoothbore infantry-support weapon with optical sights, an FAP/FN FAL spotting rifle, and a two-wheel adjustable carriage. Falklands War evidence directly documents the closely related Modelo 1968 Czekalski in Argentine service, while the M1974 designation is best supported as the improved FMK-1 ammunition and export-era standard.
BGM-71 TOW, Heavy anti-tank guided missile, Infantry WeaponsInfantry WeaponsBGM-71 TOWHeavy anti-tank guided missileThe BGM-71 TOW is a U.S. heavy anti-tank guided missile built around tube launch, optical tracking, and command guidance through a wire or later radio-frequency link. Developed by Hughes and now produced and upgraded by Raytheon, the family spans dismounted launchers, HMMWVs, Bradley and Stryker vehicles, light armored vehicles, and helicopters. Its record runs from helicopter launches in the Vietnam War through Gulf War, Iraq, Afghanistan, Syria, Yemen, and Ukrainian service or transfer evidence.

Sources

Recoilless WeaponsPublisher: Small Arms Survey | Note: Supports the recoilless-gun family context and the general design role of recoilless weapons, including the 106 mm class. | Accessed: 2026-06-29106mm M40Publisher: WeaponSystems.net | Note: Supports the M40 identification, origin, crew-served type, weight, length, ammunition, carriage, muzzle velocity, range data, and 1955 service context. | Accessed: 2026-06-29RIA Self-Guided Tour: The OntosPublisher: U.S. Army | Note: Supports 1955 Vietnam War conflict usage by documenting the M50 Ontos in U.S. Marine Corps service in Vietnam with six M40A1C recoilless rifles and its field-support role; also supports the M40A1C Ontos variant context. | Accessed: 2026-06-29Ancient U.S. Weapon Makes a Surprise Reappearance in SyriaPublisher: WIRED | Note: Supports conflict usage for the 2001 War in Afghanistan, 2011 First Libyan Civil War, 2011 Syrian Civil War, and 1955 Vietnam War by reporting fielded M40 use or M40-equipped Ontos service in each conflict context. | Accessed: 2026-06-29Rebel Forces in Northern MaliPublisher: Conflict Armament Research / Small Arms Survey | Note: Supports 2012 Mali War conflict usage by documenting 106 mm recoilless rifles among rebel forces' weapons and related materiel in northern Mali. | Accessed: 2026-06-29The Relevance of the Army Museum EnterprisePublisher: U.S. Army Center of Military History | Note: Supports M40A1 description, spotting-rifle component context, and 1980 Iran-Iraq War conflict usage by noting Iranian receipt of M40A1 recoilless rifles to fight Iraq. | Accessed: 2026-07-06M274 with M40 in AAFM.jpgPublisher: Wikimedia Commons | Note: Image provenance for a public-licensed M274 utility platform carrying an M40 recoilless rifle. | Accessed: 2026-06-29M40 recoilless rifle at Hoi An Museum.jpgPublisher: Wikimedia Commons | Note: Image provenance for a public-licensed museum photograph of an M40 recoilless rifle. | Accessed: 2026-06-29M40 recoilless rifle, Greek infantry, 1997.jpgPublisher: Wikimedia Commons | Note: Image provenance for a public-licensed photograph showing the M40 in Greek infantry service. | Accessed: 2026-06-29Infantry Support and Anti-tank Weapons in Latin AmericaPublisher: Small Arms Defense Journal | Note: Supports the compact Al-Jawad turret relationship and the 106 mm recoilless-gun mounting context on the vehicle. | Accessed: 2026-06-29