The Ultralightweight Field Howitzer (UFH), designated M777 in the US, was selected to replace the existing inventory of M198 155mm towed howitzers by a joint US Army / Marine Corps initiative in 1997.
The first of five EMD systems was delivered in June 2000. A low-rate initial production (LRIP) contract for 94 systems was awarded in November 2002.
Operational testing with the USMC, during which nearly 12,000 artillery rounds were fired by four production systems, was completed in December 2004. A contract for full-rate production of 495 systems was awarded to BAE Systems in April 2005, and the following month the USMC began fielding the M777 with the 11th Marines unit at Twentynine Palms in California.
In July 2004, the M777 howitzer completed a series of airlift tests with the US Marine Corps MV-22 Osprey tiltrotor aircraft. The M777 was carried as an external load for a distance of 69nm during the tests.
The first 18 systems were delivered to the US Army’s 2nd Battalion, 11th Field Artillery in Hawaii in October 2006.
The M777 howitzer has been developed by BAE Systems Land Systems (RO Defence, formerly the Armaments Group of Vickers Shipbuilding and Engineering Ltd) at Barrow-in-Furness.
United Defense LP of Pascagoula, Mississippi, is responsible for the final assembly, test and delivery of production systems for the US.
More than 1,200 M777 howitzers have been ordered by the armed forces of the US, Canada, Australia, and India.
M777 howitzer A1 and A2 variants
The M777 is the artillery system for the Stryker Brigade Combat Teams (SBCT). The M777 is normally operated by a crew of eight men, but can be operated with a reduced detachment of five.
The systems fitted with the digital fire control system are designated M777A1, and those with the software update that allows the firing of the Excalibur projectile, M777A2.
M777A2 received full material release in July 2007, clearing the upgrade for fielding. All M777A1 systems were upgraded to the A2 standard.
The M777 was deployed by the US Army and Marine Corps to Afghanistan in December 2007 and to Iraq in 2008.
The Excalibur projectile was first deployed in Afghanistan in March 2008.
By August 2008, over 400 systems had been delivered to the US Army and USMC.
The projectile was inducted by the Indian Army in October 2019.
Design and construction of the Ultralightweight Field Howitzer
The construction of the M777 makes extensive use of titanium and titanium castings, enabling a weight reduction of 3,175kg (7,000lb) compared to the M198 howitzer, which it replaces in the US Army and USMC inventory. The titanium is supplied by RTI International metals of Niles, Ohio.
The M777 matches the firepower of current generation 155mm towed systems at less than half the weight. The howitzer is equipped with a 39-calibre barrel. The muzzle velocity (at Charge 8 super) is 827m/s.
The maximum firing range is 24.7km with unassisted rounds and 30km with rocket-assisted rounds. The M777A2 can fire the Raytheon / Bofors XM982 Excalibur GPS / Inertial Navigation-guided extended-range 155mm projectiles using the Modular Artillery Charge Systems (MACS). Excalibur has a maximum range of 40km and an accuracy of 10m.
First firing trials of the M777A1 with Excalibur took place in August 2003, while the first production rounds were delivered in September 2006. Excalibur successfully completed limited user test in March 2007. It was first fielded in Iraq in May 2007 and in Afghanistan in February 2008.
The M777 is able to deliver up to five rounds a minute under intense firing conditions and is able to provide a sustained rate of fire of two rounds a minute.
The LRIP systems employ an optical sighting system for direct and indirect firing by day or night. Full production systems are fitted with the General Dynamics Armament Systems Towed Artillery Digitisation (TAD) system. LRIP systems will be retrofitted with TAD.
The TAD digital fire control system provides on-board ballistic computation, navigation, pointing and self-location, providing greater accuracy and faster reaction times, and also includes a laser ignition system, electric drives for the howitzer’s traverse and elevation, and a powered projectile rammer.
The M777 has a production weight of 3,745kg and can be transported by helicopter, transporter aircraft and ship. The howitzer can be towed by an air-braked 4×4 vehicle greater than 2.5t.
Horstman Defence Systems of the UK provided the hydrostrut suspension system. The maximum towed road speed is 88km/h and the towed cross-country speed is 50km/h.
The load on the towing eye is rated at 60kg, while the towing ground clearance is up to 660mm.
|Mass||4,200 kg (9,300 lb)|
|Length||Combat: 10.7 m (35 ft 1 in)
Travel: 9.5 m (31 ft 2 in)
|Barrel length||5.08 m (16.7 ft)/L39|
|Shell||M107, M795, ERFB, M982|
|Caliber||155 mm (6.1 in)|
|Elevation||0° to +71.7°|
|Rate of fire||Normal: 2 rpm
Maximum: 7 rpm
|Muzzle velocity||Charge 8S: 827 m/s (2713.25 ft/s)|
|Effective firing range||M107: 24 km (14.9 mi)
ERFB: 30 km (18.6 mi) base bleed
M795: 28.7–37 km (17.8- 23 mi)
Excalibur: 40 km (25 mi)
- Australian Army – 54 systems (M777A2).
- Canada: 37 systems.
- India: 25 systems in service currently .(Total 145 System were on order out of which all the remaining 120 system are to be manufactured in India under the “Make in India” program)
- Saudi Arabia: 70 systems.
- United States