Artillery

M102 105 mm Howitzer

Also known as
  • M102
  • M102 howitzer
  • 105 mm M102
  • 105mm M102
  • M102 105mm lightweight towed howitzer
  • XM102

The M102 is a U.S. 105 mm lightweight towed howitzer developed at Rock Island Arsenal for airborne, air-assault, and light-infantry artillery units. It replaced heavier M101A1 guns in Vietnam, used a low aluminum carriage with 360-degree traverse, and later remained visible through Gulf War, Iraq War, and AC-130 gunship service after Army field artillery units transitioned to the M119.

M102 105 mm Howitzer, 105 mm lightweight towed howitzer, Artillery
Image source: Commons M102 Iraq 2004 Image

Role in Conflicts

1955 Vietnam War
Fire Support
Side
United States and South Vietnam

U.S. Army field artillery history and Army Historical Foundation coverage identify the M102 as received in Vietnam in 1966, first issued to 1st Battalion, 21st Field Artillery, and fired by U.S. artillery units in the Vietnam theater.

Profile / Specs

Profile

Origin
United States
Type
105 mm lightweight towed howitzer
Service note
Entered U.S. Army service in the mid-1960s; retained in National Guard and AC-130-related service after Regular Army M119 replacement
Designer
Rock Island Arsenal
Designed
1962 prototype and design work
Produced
1964-1973
Number built
Over 1,100 M102 howitzers produced; Army Historical Foundation and Army sources also cite about 1,150 acquired by the U.S. Army
Developed from
M101A1 105 mm howitzer replacement requirement
Developed into
M119 105 mm howitzer replacement in U.S. Army field artillery units; modified M102 cannon installations on AC-130 gunships

Specifications

Caliber
105 mm
Projectile
33 lb semi-fixed 105 mm ammunition projectile class
Weight
About 3,000-3,298 lb depending on source and configuration
Crew
Eight-person howitzer section in U.S. field manual organization
Range
11.5 km with standard charge; 15.1 km with rocket-assisted projectile
Rate of fire
Up to 10 rounds per minute initially; about 3 rounds per minute sustained
Muzzle velocity
494 m/s at charge 7
Elevation
-5 degrees to +75 degrees
Traverse
360 degrees / 6,400 mils on the firing platform
Mobility
Towed by light truck or HMMWV, helicopter transportable, and suitable for airborne delivery
Lightweight Carriage And Fire Role

The M102 was built around portability and fast all-around traverse rather than heavy-caliber destructive effect. Its aluminum wishbone carriage, firing platform, and trail roller allowed the gun to be shifted through a full circle after emplacement, while the 105 mm ammunition family kept it light enough for helicopter, light-vehicle, and airborne-unit logistics.

Air-mobile requirement

Army Rock Island coverage describes the requirement as a towed 105 mm howitzer under 3,000 pounds that could be delivered by parachute, helicopter, or assault landing.

Vietnam terrain adaptation

The XM6 firing platform was developed for M102 use in inundated and soft ground, then tested in Vietnam from September 1967.

Fire-support tradeoff

GlobalSecurity's Army-derived summary describes the M102 as compensating for smaller projectile weight with volume of fire and mobility in airmobile and light-infantry operations.

Sources: Supporting fire: Stabilizing firepower in a swamp; M102 105mm Lightweight Towed Howitzer; Field Artillery 1954-1973 Chapter 3.

Variants

The M102 record covers the towed howitzer family and the closely related XM102 prototype. AC-130 installations used a modified M102 cannon rather than a separate towed field piece.

VariantConfigurationDesignation notes
XM102Experimental 105 mm light towed howitzer

Rock Island Arsenal material identifies XM102 as the experimental version, with prototype completion in 1962 and production beginning in 1964.

Sources: Supporting fire: Stabilizing firepower in a swamp, RIA Self-Guided Tour: XM102 Experimental 105MM Light Towed Howitzer

M102 AC-130 cannon installationModified side-firing gunship armament

The National Museum of the U.S. Air Force describes the M102 105 mm cannon as adapted for AC-130 gunships after a 40 mm side-firing gun was replaced to increase firepower.

Sources: National Museum M102 105mm Cannon

Predecessor And Replacement

The M102 sits between two public 105 mm U.S. howitzer records: it replaced the M101A1 in Vietnam-era airborne and light infantry units, then was itself replaced by the M119 in Regular Army field artillery.

Compatible itemItem typeCompatibility evidence
M101 105 mm Howitzer, 105 mm towed field howitzer, ArtilleryM101 105 mm HowitzerEarlier 105 mm towed howitzer

Army Vietnam history describes the M102 replacing the M101A1 in Vietnam because the newer gun was lighter, had better on-carriage traverse, and suited heliborne operations.

Sources: Field Artillery 1954-1973 Chapter 3

M119, 105 mm lightweight towed howitzer, ArtilleryM119Later 105 mm lightweight towed howitzer

Army Historical Foundation history identifies the M119 as the U.S. Army replacement for the M102 in Regular Army field artillery units beginning in 1989.

Sources: Army Historical Foundation M102 105mm Howitzer

Gunship Installation

The towed M102 and the AC-130-mounted 105 mm cannon are not identical battlefield packages, but Air Force museum and Army history sources tie the gunship armament directly to the M102 cannon.

CarrierCarrier typeCarriage evidence
AC-130 gunship, Heavily armed fixed-wing gunship, Aircraft & UAVsAC-130 gunshipSide-firing gunship

The National Museum of the U.S. Air Force states that a modified M102 105 mm cannon replaced one side-firing 40 mm gun on AC-130 gunships to increase firepower.

Sources: National Museum M102 105mm Cannon

Timeline

M102 105 mm Howitzer Key Events

  1. XM102 prototypes completed

    Army Rock Island coverage says XM102 prototype work was completed in 1962 as the Army sought a 105 mm howitzer under 3,000 pounds for airborne and air-assault delivery.

    Sources: Supporting fire: Stabilizing firepower in a swamp

  2. Production begins

    Army reporting records M102 production starting in 1964 and continuing into the early 1970s.

    Sources: Supporting fire: Stabilizing firepower in a swamp

  3. First M102s issued in Vietnam

    Army Vietnam field artillery history states that the first M102s were issued to 1st Battalion, 21st Field Artillery, in March 1966.

    Sources: Field Artillery 1954-1973 Chapter 3

  4. XM6 platform tested with the M102 in Vietnam

    Six XM6 airmobile firing-platform prototypes were sent to Vietnam as proof-of-concept equipment for M102 operations in inundated and soft ground.

    Sources: Supporting fire: Stabilizing firepower in a swamp

  5. Regular Army replacement begins

    Army Historical Foundation history states that the U.S. Army began replacing the M102 with the M119 in Regular Army field artillery units while National Guard battalions retained M102s.

    Sources: Army Historical Foundation M102 105mm Howitzer

  6. M102 documented at Camp Taji

    A Commons-hosted Operation Iraqi Freedom II photograph identifies an M102 from Battery A, 1st Battalion, 206th Field Artillery at Fire Base Paris, Camp Taji, Iraq.

    Sources: Commons M102 Iraq 2004 Image

  7. AC-130J 105 mm gun decision

    Army Historical Foundation history notes that Air Force Special Operations Command requested inclusion of the M102-derived 105 mm gun on the AC-130J Ghostrider in early 2015.

    Sources: Army Historical Foundation M102 105mm Howitzer

Media

M102 105 mm Howitzer Images

M102 105 mm Howitzer, 105 mm lightweight towed howitzer, Artillery - view 1
Source: Commons M102 Firing Image
M102 105 mm Howitzer, 105 mm lightweight towed howitzer, Artillery - view 2
Source: Commons M102 Sand Eagle Image
Related Weapon Systems
M119, 105 mm lightweight towed howitzer, ArtilleryArtilleryM119105 mm lightweight towed howitzerThe M119 is the U.S. 105 mm lightweight towed howitzer derived from the British L119 light gun and built around air-mobile infantry fire support. The M119A3 variant adds digital fire control, self-location, and communications upgrades while retaining a light carriage that can be moved by trucks, cargo aircraft, or helicopter. U.S. Army sources place the type in Gulf War, Iraq War, and Afghanistan service, and Ukrainian forces later received American 105 mm howitzers during the 2014 Russia-Ukraine War.
M198 155 mm howitzer, 155 mm towed howitzer, ArtilleryArtilleryM198 155 mm howitzer155 mm towed howitzerThe M198 is a U.S.-designed 155 mm towed howitzer developed at Rock Island Arsenal to replace older M114-series guns. Its split-trail carriage, nine-person crew, air-transportable layout, and 22-30 km range made it a standard U.S. Army and Marine Corps fire-support weapon before the lighter M777 replaced it in U.S. service. Direct conflict sourcing now traces M198 fielding from Desert Storm through U.S. use in Afghanistan and Iraq, Islamic State capture and cross-border use in Iraq and Syria, Iraq-aligned militia firing, and coalition-backed Iraqi Army live-fire training.
L118 Light Gun, 105 mm towed light howitzer, ArtilleryArtilleryL118 Light Gun105 mm towed light howitzerThe L118 Light Gun is a British 105 mm towed howitzer built for airborne, commando, and light-force artillery. It can be towed by a medium-weight vehicle or carried underslung by a Chinook helicopter, and BAE Systems says its 105 mm ammunition family includes HE, illumination, target-marking, smoke, and propelling-charge options. This family record also covers the L119 branch, the NATO/M1-ammunition variant supplied to Ukraine, while the U.S. M119 derivative has its own linked entry.

Sources

Supporting fire: Stabilizing firepower in a swampPublisher: U.S. Army | Note: Supports XM102 development, component production, Rock Island Arsenal carriage and recoil work, 1962 prototypes, 1964-1973 production, airborne/airmobile requirement, and direct 1955 Vietnam War use context because XM6 platforms were sent to Vietnam for use with M102 howitzers in inundated and soft ground. | Accessed: 2026-07-06RIA Self-Guided Tour: XM102 Experimental 105MM Light Towed HowitzerPublisher: U.S. Army | Note: Official Rock Island Arsenal article supporting XM102 prototype identity, Rock Island Arsenal design role, M102 mobility, direct 1955 Vietnam War use context because the M102 entered service during the Vietnam escalation, direct 2003 Iraq War use context because the M102 served through Operation Iraqi Freedom, and continuing AC-130 gunship connection. | Accessed: 2026-07-06Field Artillery 1954-1973 Chapter 3Publisher: U.S. Army Center of Military History | Note: Supports 1955 Vietnam War direct use by U.S. artillery units, including 1966 receipt of M102s in Vietnam, first issue to 1st Battalion, 21st Field Artillery, replacement of M101A1 guns, and mobility/traverse advantages. | Accessed: 2026-07-06Army Historical Foundation M102 105mm HowitzerPublisher: The Army Historical Foundation | Note: Supports M102 service history, Rock Island Arsenal development context, M101A1 replacement, specifications, direct 1955 Vietnam War use by U.S. artillery units, direct 1990 Gulf War use by airborne, air-assault, or light-infantry units in Iraq during the Persian Gulf War, direct 2003 Iraq War use with 1-206 FA in Iraq in 2004, M119 replacement, exports, captured South Vietnamese examples, and AC-130 gunship use. | Accessed: 2026-07-06M102 105mm Lightweight Towed HowitzerPublisher: GlobalSecurity.org | Note: Supports Army-derived M102 overview, airmobile and light-infantry role, transportation modes, U.S. Army acquisition quantity, direct 1955 Vietnam War use context because M102s were received in Vietnam in 1966 and issued to 1st Battalion, 21st Field Artillery, plus range, rate of fire, muzzle velocity, traverse, elevation, carriage, and firing-platform details. | Accessed: 2026-07-06National Museum M102 105mm CannonPublisher: National Museum of the United States Air Force | Note: Supports M102 105 mm cannon identity, direct 1955 Vietnam War use context because the cannon first saw U.S. Army service in Southeast Asia in 1966, AC-130 gunship adaptation, and U.S. Air Force museum imagery. | Accessed: 2026-07-06Commons M102 Iraq 2004 ImagePublisher: Wikimedia Commons | Note: Supports the primary image and direct 2003 Iraq War context: Battery A, 1st Battalion, 206th Field Artillery M102 at Fire Base Paris, Camp Taji on 2004-05-29, with counter-battery and close fire-support caption context. | Accessed: 2026-07-06Commons M102 Firing ImagePublisher: Wikimedia Commons | Note: Supports gallery image provenance for a public-domain U.S. Army image of B Battery, 7th Battalion, 9th Field Artillery Regiment firing an M102 during a 1984 live-fire exercise at Pohakuloa Training Area. | Accessed: 2026-07-06Commons M102 Sand Eagle ImagePublisher: Wikimedia Commons | Note: Supports gallery image provenance for a released U.S. Department of Defense/National Archives image of an 82nd Airborne Division crew handling an M102 during Exercise SAND EAGLE '89. | Accessed: 2026-07-06FM 6-70 105-MM Howitzer Light M102 TowedPublisher: U.S. Department of the Army | Note: Supports U.S. field-manual context for M102 section operation, crew organization, firing and traveling drill, and technical-service framing. | Accessed: 2026-07-06