Concepts & Programs HomeProgramsFocus Area 4: Modernization & TechnologyPart 4: Fire SupportLW155
Lightweight 155mm Howitzer

U.S. Marines with the 11th Marine Expeditionary Unit fire their M777 Howitzer during a fire mission in northern Syria as part of Combined Joint Task Force - Operation Inherent Resolve, Mar. 24, 2017. The 11th MEU was deployed in the Asia-Pacific and Middle Eastern regions and acted as a rapid response force available to conduct operations in support of U.S. Forces and allied and partner nations. More than 60 regional and international nations have joined together to enable partnered forces to defeat ISIS and restore stability and security. CJTF-OIR is the global Coalition to defeat ISIS in Iraq and Syria. (U.S. Marine Corps photo by Cpl. Zachery C. Laning)


The M777A2 (LW155) is a joint Marine Corps- Army program to develop, produce, field and sustain a towed 155mm howitzer that provides increased mobility, survivability, deploy ability and sustainability in expeditionary operations throughout the world. The M777A2 is a direct and general-support artillery system that has replaced the M198 155mm medium towed howitzer in both Services. It has incorporated innovative design technologies to overcome deficiencies inherent in the M198.

The M777A2 is the first ground combat system whose major structures are made of high-strength titanium alloy resulting in a weight savings of more than 7,000 pounds when compared to the M198 system. The system also makes extensive use of hydraulics to operate the breech, load tray, recoil and wheel arms. This combination results in a system that emplaces three times faster and displaces four times faster than its predecessor, making it 70% more survivable than the M198 while traversing 32 percent more terrain worldwide.

The M777A2 has been in service since 2005. The Marine Corps currently maintains an approved acquisition objective of 360 M777A2 howitzers, while the Army has purchased 488 systems. The Army took the final howitzer delivery in 2013.

Fieldings to the USMC have been completed and Army fieldings continue through 2018. The Program Office continues to support modification and refresh efforts through active retrofits. The Canadian Army purchased 37 base-model M777s under a Foreign Military Sale contract while the Australian Army has purchased 54 M777A2s. The Government of India signed a Letter of Offer and Acceptance for 145 M777A2 howitzers and support equipment in December 2016. An M777A2 Life Cycle Sustainment contract was awarded 30 April 2013 to BAE Systems UK, with the potential to sustain the system through 2023.

Operational Impact

The M777A2 can fire the precision-guided Excalibur munitions up to 24 miles with sufficient accuracy to reduce noncombatant casualties and collateral damage. The M777A2 has consistently achieved an operational availability greater than 90 percent supporting multiple combat operations, including Operation Enduring Freedom (OEF) for Marine Corps, Army and Canadian forces.

Program Status

The M777A2 has been in-service with the Marine Corps since 2005. The Marine Corps has taken final delivery of its 511 howitzers. In 2017, PMTAS received initial USMC and Army funding to commence production of a chrome lined cannon tube which will eventually replace the original steel tubes. Chrome lined tubes are easier to clean and wear slower than the original design, further extending the M777A2 useful life.


BAE, Barrow in Furness, UK