Artillery

Rheinmetall Rh-120

Also known as
  • Rheinmetall 120 mm smoothbore gun
  • Rh-120
  • Rh 120
  • L44
  • L55
  • L55A1
  • M256

The Rheinmetall Rh-120 is Germany's 120 mm smoothbore tank-gun and ammunition family, developed from Rheinmetall's 1965-1975 smoothbore weapon-ammunition work and fielded through Leopard 2 and licensed Abrams M256 applications. The family runs from the original L44 to the longer L55 and high-pressure L55A1 branches; this relationship-only component page documents the gun lineage, barrel-length variants, ammunition interface, and modernization context rather than making independent conflict-use claims apart from host tanks.

Rheinmetall Rh-120, 120 mm smoothbore tank gun family, Artillery
Image source: Rheinmetall 120 mm gun Leopard 2E image
Profile / Specs

Profile

Origin
Germany
Built by
Rheinmetall
Type
120 mm smoothbore tank gun family
Service note
Introduced with late Cold War main battle tanks and retained in modern Leopard 2, Abrams, and Challenger 3 firepower packages
Designer
Rheinmetall
Designed
1965-1975 smoothbore weapon-ammunition development period
Unit cost
Not publicly documented as a standalone gun in this catalog record
Produced
Late 1970s to present in L44, L55, and L55A1 family forms
Number built
Not publicly documented as a standalone gun family total

Specifications

Caliber
120 mm
Ammunition interface
120 mm x 570 smoothbore tank ammunition with combustible cartridge case context
Bore
Smoothbore
L44 barrel length
5,300 mm
L55/L55A1 barrel length
6,600 mm
L44 barrel weight
1,190 kg
L55/L55A1 barrel weight
1,350 kg
Weapon weight without protection
3,030 kg for L44; 3,360 kg for L55/L55A1
Major gun branches
L44, L55, and L55A1
Ammunition context
Rheinmetall identifies DM63A1 as usable from L44 and L55, while DM73 requires the high-pressure L55A1 gun
Gun And Ammunition Branches

The Rh-120 family is best read as a weapon-ammunition interface, not only as a barrel. Rheinmetall links the gun line to 120 mm x 570 ammunition and distinguishes the L44, longer L55, and high-pressure L55A1 by barrel data and ammunition compatibility.

L44 baseline

5,300 mm barrel; Rheinmetall identifies it with Leopard 2 and licensed Abrams M256 applications.

L55 branch

6,600 mm barrel; Rheinmetall says the longer barrel and optimized material increase velocity and engagement range compared with L44.

L55A1 branch

High-pressure L55 development; Rheinmetall links it to DM73, Leopard 2 modernization, and Challenger 3 firepower packages.

Variants

Rheinmetall's L44, L55, and L55A1 names describe branches of the same 120 mm smoothbore tank-gun family. Official technical data gives a 5,300 mm L44 barrel and a 6,600 mm L55/L55A1 barrel, so this entry cites measured lengths rather than relying on designation shorthand alone.

VariantConfigurationDesignation notes
L44Original 120 mm smoothbore branch

Rheinmetall identifies the L44 with Leopard 2 and the licensed M256 used on M1A1/A2 Abrams tanks; its published technical data lists a 5,300 mm barrel.

Sources: Rheinmetall 120 mm Smoothbore Gun, Rheinmetall 120 mm System House

L55Longer-barrel development

Rheinmetall describes the L55 as based on the L44 with optimized barrel material and a longer 6,600 mm barrel, converting more firing energy into projectile velocity.

Sources: Rheinmetall 120 mm Smoothbore Gun, Rheinmetall 120 mm System House

L55A1High-pressure modernization branch

Rheinmetall describes the L55A1 as a high-pressure gun based on L55, qualified and in service since 2019; Rheinmetall and UK sources connect it to Challenger 3 and DM73-class ammunition context.

Sources: Rheinmetall 120 mm System House, Rheinmetall Challenger product page, DE&S Challenger 3 Crewed Live Firing

Installed Platforms

Catalog links are limited to host vehicles already represented as public weapon records and supported by source-backed armament descriptions.

CarrierCarrier typeCarriage evidence
Leopard 2, Main battle tank, TanksLeopard 2Main battle tank

Rheinmetall identifies the L44 with Leopard 2 and describes the L55 as a later Leopard 2 main armament branch for higher projectile velocity and longer-range engagements.

Sources: Rheinmetall 120 mm Smoothbore Gun, Rheinmetall 120 mm System House

M1 Abrams, Main battle tank, TanksM1 AbramsMain battle tank

Rheinmetall identifies the L44 as the NATO smoothbore gun adopted for Abrams M1A1 under U.S. license, while U.S. Army imagery and reporting identify M1A2 Abrams crews firing the Rheinmetall M256 120 mm smoothbore tank gun.

Sources: Rheinmetall 120 mm Smoothbore Gun, U.S. Army Adazi live fire

Evidence boundary

This component record does not copy host-tank conflict use into the gun page unless a direct source separately identifies the Rh-120 gun itself in the exact conflict.

Sources: Rheinmetall 120 mm Smoothbore Gun

Timeline

Rheinmetall Rh-120 Key Events

  1. 120 mm smoothbore system development

    Rheinmetall traces its 120 mm smoothbore weapon-ammunition technology and combustible-cartridge-case ammunition family to this development period.

    Sources: Rheinmetall 120 mm System House

  2. U.S. comparative test and Abrams adoption

    Rheinmetall says its 120 mm weapon-ammunition interface prevailed in U.S. comparative testing and led to adoption of the smoothbore technology for Abrams main armament.

    Sources: Rheinmetall 120 mm System House

  3. Licensed NATO spread

    Rheinmetall says that after 1980, 120 mm smoothbore technology was licensed to multiple countries and became a dominant Western and NATO tank-gun standard.

    Sources: Rheinmetall 120 mm System House

  4. L55A1 qualified and in service

    Rheinmetall identifies the L55A1 as a high-pressure gun based on L55 and says it has been qualified and in service since 2019.

    Sources: Rheinmetall 120 mm System House

  5. Challenger 3 L55A1 production start

    RBSL reported that the first two Rheinmetall 120 mm smoothbore L55A1 weapons for Challenger 3 testing entered production at Unterluess.

    Sources: RBSL First Smoothbore Weapons

  6. Challenger 3 crewed live firing

    DE&S reported Challenger 3 crewed live firing trials and identified the tank's gun as the Rheinmetall-manufactured 120 mm smoothbore L55A1.

    Sources: DE&S Challenger 3 Crewed Live Firing

Media

Rheinmetall Rh-120 Videos

Rheinmetall Rh-120 Images

Rheinmetall Rh-120, 120 mm smoothbore tank gun family, Artillery - view 1
Source: Rheinmetall 120 mm breech image
Rheinmetall Rh-120, 120 mm smoothbore tank gun family, Artillery - view 2
Source: Rheinmetall 120 mm Leopard 2 gun image
Rheinmetall Rh-120, 120 mm smoothbore tank gun family, Artillery - view 3
Source: M1A2 Abrams main gun maintenance image
Related Weapon Systems
Leopard 2, Main battle tank, TanksTanksLeopard 2Main battle tankThe Leopard 2 is Germany's long-running NATO-standard main battle tank family, built around Rheinmetall 120 mm smooth-bore guns, modular protection, and repeated fire-control upgrades. The A4 became the widely exported baseline branch, the A6/A6M brought the longer L55 gun and mine-protection changes into combat service, and later A7/A8 work adds digital systems, programmable ammunition, and active-protection integration. Combat documentation spans Canadian A6M use in Afghanistan, Turkish A4 losses in Syria, and donor-supplied Leopard 2A4, Leopard 2A6, and Strv 122 tanks in Ukrainian service.
M322 or M338 120 mm APFSDS-T tank projectile, 120 mm APFSDS-T tank-gun cartridge, MunitionsMunitionsM322 or M338 120 mm APFSDS-T tank projectile120 mm APFSDS-T tank-gun cartridgeThe M322 and M338 are Israeli 120 mm APFSDS-T tank-gun cartridges in Elbit Systems' NATO-standard smoothbore ammunition line. Elbit separates M322 as a second-generation NC-NG-propellant round and M338 as a third-generation LOVA-propellant round, both using tungsten-alloy penetrators for L44/L55 120 mm guns; OSMP identified one Israeli APFSDS-T round in the Israel and Gaza 2023-2026 collection as either M322 or M338.
Strv 122, Main battle tank, TanksTanksStrv 122Main battle tankThe Strv 122, formally Stridsvagn 122, is Sweden's Leopard 2-based main battle tank, adapted for Swedish service with a four-person crew, a 120 mm smoothbore gun, 7.62 mm machine guns, smoke launchers, reinforced protection, and a digital command-support system. Sweden donated about ten tanks to Ukraine in 2023, trained Ukrainian crews in Sweden, and later contracted to modernize its remaining Strv 122 fleet into the Strv 123A standard while buying new Leopard 2A8-based Strv 123B tanks.

Sources

Rheinmetall 120 mm Smoothbore GunPublisher: Rheinmetall | Note: Supports manufacturer, background, and technical context for Rheinmetall's 120 mm smoothbore gun family, including L44 use on Leopard 2 and Abrams M1A1 and L55 development for longer-range, higher-performance tank ammunition. | Accessed: 2026-07-13Rheinmetall 120 mm System HousePublisher: Rheinmetall | Note: Supports development chronology, L44/L55/L55A1 technical data, Abrams M256 license context, ammunition interface details, and L55A1/DM73 compatibility limits. | Accessed: 2026-07-13Rheinmetall Challenger product pagePublisher: Rheinmetall | Note: Supports current L55A1 context by identifying the Challenger 3 firepower upgrade with Rheinmetall's 120 mm smoothbore L55A1 cannon. | Accessed: 2026-07-13RBSL First Smoothbore WeaponsPublisher: Rheinmetall BAE Systems Land | Note: Supports Challenger 3 L55A1 production context by reporting that the first two Rheinmetall 120 mm smoothbore L55A1 weapons entered production for testing and trialling. | Accessed: 2026-07-13RBSL Challenger 3 Major MilestonePublisher: Rheinmetall BAE Systems Land | Note: Supports Challenger 3 L55A1CR3 test-firing and integration context for the British CR3 main battle tank programme. | Accessed: 2026-07-13DE&S Challenger 3 Crewed Live FiringPublisher: Defence Equipment & Support | Note: Supports Challenger 3 crewed live-firing context and identifies the tank as equipped with a Rheinmetall-manufactured 120 mm smoothbore L55A1 cannon. | Accessed: 2026-07-13U.S. Army Adazi live firePublisher: U.S. Army | Note: Supports Abrams platform relationship context by identifying U.S. Army M1A2 Abrams crews firing the Rheinmetall M256 120 mm smoothbore tank gun during a live-fire exercise. | Accessed: 2026-07-13Rheinmetall 120 mm gun Leopard 2E imagePublisher: Wikimedia Commons | Note: Supports image provenance for a reusable close-up photograph of the Rheinmetall 120 mm gun on a Leopard 2E. | Accessed: 2026-07-13Rheinmetall 120 mm breech imagePublisher: Wikimedia Commons | Note: Supports image provenance for a reusable photograph of a Rheinmetall 120 mm L44 smoothbore gun breech in a Leopard 2A4. | Accessed: 2026-07-13Rheinmetall 120 mm Leopard 2 gun imagePublisher: Wikimedia Commons | Note: Supports image provenance for a reusable photograph of a Rheinmetall 120 mm gun on a Leopard 2. | Accessed: 2026-07-13M1A2 Abrams main gun maintenance imagePublisher: Wikimedia Commons | Note: Supports image provenance for a public-domain U.S. Army photograph of M1A2 Abrams main-gun maintenance, used as host-platform gun context. | Accessed: 2026-07-13