[10] 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.

[22] 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.

[26][27] 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.

[29] 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 Operational Requirements Document (ORD) of May 1997 called for 200,000 rounds of an unguided munition with increased range at an estimated cost of $4,000/round, and Texas Instruments was awarded the initial EMD contract on 23 January 1998.

In November 2001 the volume was cut to 76,677 rounds and soon after this was further reduced to 61,483,[37] but the developers were encouraged by the Indian experience of using Russian Krasnopol guided shells against Pakistani bunkers in the Kargil War of 1999.

[40] Raytheon was awarded a $42.7 million contract for production of 335 Excalibur projectiles and related test articles and services in June 2006 for that fiscal year.

[41] In August 2006, technical problems relating to environmental sensitivity and GPS signal lock were discovered, pushing the expected in-service date to spring 2007.

[44] Increment Ia-2 achieved a 40 kilometers (25 mi) range in a live-fire demonstration in April 2007 and in July the Army Acquisition Executive approved the Milestone C decision for Ia-2 to enter low-rate production.

Normally a Nunn-McCurdy breach signals a program in trouble, but a 2012 RAND report concluded that the unit cost increases were caused by the cuts in procurement numbers: fewer shells were needed for the same effect, due to the improved accuracy of modern artillery.

Because the M982 is so accurate, the risks of friendly-fire casualties and collateral damage are no longer deterrents to using gun artillery in urban environments, and the Excalibur is sometimes called in only 50 m (160 ft) away from friendly infantrymen.

In February 2012, a U.S. Marine Corps M777 howitzer in Helmand province, Afghanistan, fired a single Excalibur round that killed a group of insurgents at a Marine-record range of 36 kilometers (22 mi).

[51] In February 2014, the U.S. Army and Raytheon fired 30 Excalibur Ib shells at test targets to confirm the performance and reliability of the configuration before full-rate production.

The test was to validate the LST's ability to survive being fired from a howitzer and was initialized with GPS coordinates, then a laser designator guided the round to the target.

India will use this ammunition from all 155 mm caliber guns including M777, Haubits FH77, Dhanush and K9 Vajra-T.[57] In April 2024, Hanwha Aerospace conducted test fires of the M982A1 Excalibur Increment Ib at Yuma Proving Ground using Norwegian K9 VIDAR variant.

Its primary uses would be to allow warships to accurately fire shells against land targets in support of troops ashore and inexpensively destroy fast attack craft (FAC) at longer ranges.