M982 Excalibur

The M982 Excalibur (previously XM982) is a 155 mm extended-range guided artillery shell developed in a collaborative effort between the U.S. Army Research Laboratory (ARL) and the United States Army Armament Research, Development and Engineering Center (ARDEC). The Excalibur was developed and/or manufactured by prime contractor Raytheon Missiles & Defense, BAE Systems AB (BAE Systems Bofors) and other subs and primes in multiple capacities such as Camber Corporation and Huntington Ingalls Industries. It is a GPS and inertial-guided munition capable of being used in close support situations within 75–150 meters (250–490 ft) of friendly troops or in situations where targets might be prohibitively close to civilians to attack with conventional unguided artillery fire. In 2015, the United States planned to procure 7,474 rounds with a FY 2015 total program cost of US$1.9341 billion at an average cost of US$258,777 per unit. By 2016, unit costs were reduced to US$68,000 per round. Versions that add laser-guidance capability and are designed to be fired from naval guns began testing in 2015. By October 2018, over 1,400 rounds had been fired in combat.

Excalibur, named after the mythical sword of King Arthur, was developed as a longer-range alternative to conventional artillery shells, with GPS guidance for improved accuracy. Excalibur has a range of approximately 40 to 57 kilometers (25 to 35 mi) depending on configuration, with a circular error probable (CEP) of four meters (13 ft), while unguided Western artillery shells can land up to 150 meters (490 ft) from the target at a range of 24 km (15 mi). While much more expensive at $68,000 per shell compared to an $800 unguided M777 shell, it is less expensive than the $150,000 rocket used in US guided-missile systems like M142 HIMARS and M270 Multiple Launch Rocket System. Excalibur's extended range is achieved through the use of folding glide fins, which allow the projectile to glide from the top of a ballistic arc toward the target. A lower cost alternative to the Excalibur is to use the US Army designed M1156 precision guidance kit to turn existing 155 mm shells into precision weapons.

The munition was co-developed by United States-based Raytheon Missiles & Defense (guidance system) and the Swedish BAE Systems Bofors (body, base, ballistics, and payload). Excalibur is used to minimize collateral damage, for targets beyond the range of standard munitions, for precise firing within 150 meters (490 ft) of friendly troops, or when terrain prevents direct fire. It has a multi-function fuze that can be programmed to explode in the air, once it hits a hard surface, or after it penetrates a target. One Excalibur projectile can accurately hit an intended target that would require the use of between 10 and 50 unguided artillery rounds.

Initial combat experience with Excalibur in Iraq in the summer of 2007 was highly successful, with 92% of rounds falling within four meters (13 ft) of their targets. Its performance was so impressive that the U.S. Army planned to increase production to 150 rounds per month from the previous 18 rounds per month. In 2012, Excalibur rounds reached new record ranges in combat of 36 kilometres (22 mi). In December 2020, the round was successfully tested out to a range of 43.5 mi (70 km) using a supercharged propellant out of a 58-caliber-long Extended Range Cannon Artillery (ERCA) gun tube.

Self-propelled guns compatible with the Excalibur projectile are the American M109A6 Paladin and M109A7, British AS-90, German PzH 2000, South African G6, Swedish Archer and French Caesar. Towed guns compatible with the Excalibur projectile are the American M198 and M777 howitzers. According to media, Excalibur ammunition was also used with AHS Krab in 2022 in combat in Ukraine, obtaining range above 40 km (25 mi).

The U.S. Navy had considered using the Excalibur in the Zumwalt-class destroyer's Advanced Gun System following the cancelation of the Long Range Land Attack Projectile, but the plan was later abandoned.

The Excalibur has been shown to be vulnerable to GPS jamming. When shells were first supplied to Ukraine during the Russian invasion of Ukraine, they initially hit targets with a 70% efficiency rate. However, within six weeks the Russians had adapted their electronic warfare systems and reduced its efficiency to only 6%.^[vague]

There are three versions of the system. Initial development effort was toward Increment I; Milestone C decisions were to be made on Increment II and III in FY2013, with a demonstration of those capabilities by 2020.