Excalibur started as a development program in 1992. 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, but the developers were encouraged by the Indian experience of using Russian
Krasnopol guided shells against Pakistani bunkers in the
Kargil War of 1999. In March 2004 the program was merged with a Swedish/US program to create Trajectory Correctable Munitions, reflected in a new ORD in September 2004 which removed the
Dual-Purpose Improved Conventional Munition "cluster bomb" variant in favor of the discriminating munition variant. Later that year the US Army reduced its planned order to 30,000 rounds. Low-rate production of 500 rounds was approved in May 2005 and Raytheon was awarded a contract to produce 165 rounds in June 2005, In September of that year, the round was successfully demonstrated at
Yuma Proving Ground, Arizona. 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. In August 2006, technical problems relating to environmental sensitivity and GPS signal lock were discovered, pushing the expected in-service date to spring 2007. Testing in September demonstrated an actual average CEP of or better. Increment Ia-1 completed testing in early 2007 and in April that year the US Army approved an Urgent Material Release to allow deployment to Iraq. Increment Ia-2 achieved a 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. In 2008 unit cost was US$85,000. In September 2008 both Raytheon and Alliant Techsystems were awarded competitive development contracts for Increment Ib mass production, Test firings of Increment Ia-1 rounds in March 2009 revealed that the Honeywell inertial measurement unit was not up to standard, and it was replaced by a unit from Atlantic Inertial Systems. In April 2010 the US Army's planned order was cut further, from 30,000 rounds to 6,264, which increased the unit cost sufficiently that it triggered an investigation under the
Nunn–McCurdy Amendment. 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. In December 2012, Raytheon received a $56.6 million contract for
low-rate initial production of Excalibur Ib projectiles. On 10 September 2013, Raytheon received a $54 million contract for a second lot of Excalibur Ib artillery rounds. The Excalibur Ib has improved reliability and lower unit cost than the previous Excalibur Ia-1 and Ia-2. At the time of the award, over 690 Excalibur projectiles had been fired in theater. In February 2014, the US Army and Raytheon fired 30 Excalibur Ib shells at test targets to confirm the performance and reliability of the configuration before full-rate production. Projectiles were fired from Paladin and M777 howitzers at ranges from , each hitting within an average of from the target. Initial Operational Test and Evaluation (IOT&E) for the Excalibur Ib was completed in May 2014, moving the projectile closer to full-rate production. Testing of the Excalibur Ib averaged a miss distance of less than . On 31 July 2014, Raytheon received a $52 million contract to begin full-rate production of the Excalibur Ib shell. In June 2014, Raytheon successfully test-fired its Excalibur S shell with a dual-mode GPS/SAL guidance system. The variant incorporates a laser spot tracker (LST) into the Excalibur Ib shell. 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. In February 2020, Raytheon announced the Excalibur S had been successfully tested against a moving target using its laser seeker. In December 2019, the
Indian Army conducted firing trials of Excalibur guided shells in the
Pokhran Field Firing Range from one of its
M777 howitzer. India procured 600 units of the type in October the same year (500 with
CEP and 100 with
CEP). India will use this ammunition from all
155 mm caliber guns including M777,
Haubits FH77,
Dhanush and
K9 Vajra-T. In April 2024,
Hanwha Aerospace conducted test fires of the M982A1 Excalibur Increment Ib at Yuma Proving Ground using Norwegian
K9 VIDAR variant. The K9 used various fuze modes and achieved less than one meter CEP in Point Detonating mode and above the target in Height of Burst mode from away. As per reports in July 2025, the Indian Army is expected to urgently procure additional Excalibur shells following its extensive use during
Operation Sindoor. As reported on 20 November, the
Defense Security Cooperation Agency (DSCA) approved the supply of 216 Excalibur artillery shells at a cost of $47 million. Simultaneously, the supply of
Javelin missile systems including 100 missiles and 25 launcher control units at a cost of $46 million.
Excalibur N5 In September 2015, Raytheon conducted a live fire guided test flight of the Excalibur N5, a company-funded initiative to reduce the Excalibur shell to for use with naval guns mounted on destroyers and cruisers. The Excalibur Ib and N5 have 70% commonality, 99% identical software, and the same guidance and navigation unit (GNU). 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. Unguided shells from
Mark 45 naval guns have a range of , but can deliver accurate fire only out to , while small
cruise missile-carrying attack boats can launch from away. Like the land-based version, the Excalibur N5's guidance fins pop out after launch to glide the round out to longer ranges before turning nose-down and diving to the target, extending range to depending on gun barrel length; although range would be greater with
rocket assistance, cost would also be greater. Alternative seekers will be added to hit maneuvering targets, such as laser guidance that requires a spotter to designate it, and
millimeter wave radar that needs no outside guidance. ==Operators==