The
U.S. Army recognized the poor performance of the
M551 Sheridan light tank in the
Vietnam War and began the process of retiring the vehicle in 1977. A small number of Sheridans were retained in active service by the
82nd Airborne Division and the
National Guard. The Army designated the
M3 Bradley armored
reconnaissance vehicle to partially fill the Sheridan's role.
Initial efforts In the 1980s, the Army began looking for a more capable replacement for the Sheridan. During this time, a string of Army projects to update or replace the Sheridan were begun, but all ended without the Army committing to buy. Some of its efforts around this time could be described as hopelessly intermingled. in 2020 In 1979,
Army Chief of Staff General
Edward C. Meyer initiated a transformation of the
9th Infantry Division that would see the light infantry division assume many of the characteristics of the heavy division through an infusion of high or emerging technology. The so-called "High Technology Light Division" (HTLD) would require the procurement of a Mobile Protected Gun, later called the Assault Gun System (AGS), and a
Fast Attack Vehicle. The notional Mobile Protected Gun was to be armed with a kinetic gun, or possibly a missile, capable of defeating enemy armor. The lack of a production-ready assault gun was one of the key problems in the development of the division. Originally conceived to be a wheeled light armored vehicle armed with a
hypervelocity missile as its major tank-killing system. In 1980, the
U.S. Army Infantry School's Mobile Protected Gun project analyzed anti-armor weapons systems, concluding that the Army should equip its new light infantry divisions with
TOW-armed
Humvees and an unspecified 6×6 lightly armored vehicle armed with a
25 mm caliber gun. This led the
Secretary of Defense to direct the Army to use the
LAV-25 for this purpose. In 1981, the Army joined the
Marine Corps's (USMC) Mobile Protected Weapon System program, which then became known as the Mobile Protected Gun System (MPGS). However due to differing requirements, the Army and USMC ended their partnership the following year to embark on separate programs. The Army and Marine Corps were at the same time also involved in the joint LAV program. At the time, the Army planned to acquire 175 LAV-25s to fully equip the 9th Infantry Division. These interim MPGS's would be armed with a
M242 Bushmaster 25 mm cannon, with seating for the passengers replaced with ammunition racks. The Army planned to incorporate the LAV in the 9th Infantry Division as an interim armored gun system. The Army planned to replace this LAV beginning in the late 1980s with the "far-term" MPGS armed with a 75 mm gun. The Army's commitment to the program wavered somewhat, which caused Congress to withhold money for the LAV. The Army withdrew from the LAV program in December 1983.
M551 Sheridan mounting a 105 mm caliber gun in 1983 Modernization of the Sheridan was also studied by the
Infantry School. The chassis of the Sheridan was considered to be in good working order even if its problematic 152 mm caliber gun/launcher was not. Both the Marine Corps and Army explored re-gunning the Sheridan with a conventional gun. In 1983, the
Navy Surface Weapons Center mounted a 105 mm cannon to a Sheridan. One Army plan also envisioned re-gunning 120 Sheridans with 105 mm or 120 mm cannons, but this project was canceled in 1985. In any event the Army determined upgrading the Sheridan to meet the AGS requirement was not worth pursuing. The U.S. Army determined that it needed a more immediate solution for the AGS requirement. In 1985, the Army approved a
U.S. Army Training and Doctrine Command (TRADOC) recommendation to field the TOW missile-armed Humvee in the interim. The TOW-armed Humvee proved to be an inadequate substitute for the AGS in the 9th Infantry Division as it could not fire on the move and was too lightly armored. By 1983 the Armor School had come to support an Assault Gun. Instead of wheeled, it would be a tracked, lightweight, highly agile kinetic energy gun capable of killing enemy tanks and shielded by sufficient armor to protection the crew from artillery and small caliber weapons. The system had to be light enough to fly in a
C-130 aircraft. After the Army and Marine Corps parted ways on MPGS, the project morphed into the Armored/Assault Gun System. In 1983, the Army established the AGS program, sometimes called
XM4. In 1985,
Army Vice Chief of Staff General
Maxwell R. Thurman approved an amended requirement operational capability (ROC) for the AGS. Thurman's recommendation that the Army purchase 500 AGS systems went to Army Chief of Staff
John A. Wickham Jr.. and did not advocate for the program in Congress.
Senate appropriators declined the Army's request for AGS funds for
FY1986. The program office was disestablished, and the ROC retracted. The Army formalized the AGS program in April 1990 with the validation of a new ROC. An AGS "rodeo" was held in July 1990 at
Fort Bragg, North Carolina, with representative systems submitted from prospective contractors. In July 1990, the
Senate Armed Services Committee (SASC) required that the Army procure the AGS
off-the-shelf. In August, SASC directed the Army to halt work on
Armored Systems Modernization until it could conduct a competition for an AGS. The AGS program had gained political favor by this point due in part to the back-to-back successful employment of the Sheridan in two overseas operations. In December 1989, Sheridans of the 3/73 Armor, 82d Airborne Division, were airdropped into Panama as part of
Operation Just Cause. This was the first successful employment of light armor in combat. In August 1990, Sheridans were airdropped into Saudi Arabia as the spearhead of the buildup of Operation Desert Shield. In October 1990, HASC deferred the
Block III main battle tank and directed the Army to make the AGS its top priority modernization program. After having earlier tried to kill the tank, appropriators grew to appreciate the program's relatively low price tag. The Army believed that replacing the Sheridan with an off-the-shelf AGS would be less expensive and provide more capabilities than an upgraded Sheridan. It was expected to replace the Sheridan in the 3/73rd Armor and
TOW missile-armed Humvees in the
2nd Armored Cavalry Regiment (2nd ACR). In 1991, the Senate and
House Armed Services Committees joined in directing the Army to integrate the
turret and
Watervliet Arsenal EX35 gun of the LAV-105 with an AGS chassis. A joint program was balked at by both services, who believed the two platforms were mismatched. The Army issued a draft
request for proposals (RfP) in May 1991. The Army published the RfP in August incorporating changes as a result of feedback from industry and Congress, the latter of which had directed the Army to require the EX35 gun. Army Acquisition Executive Stephen K. Conver became concerned that the AGS program was becoming laden with unnecessary requirements that would increase costs and development time, as well as limit the number of interested contractors. •
General Dynamics Land Systems (GDLS) and Teledyne Continental Motors submitted a version of the Teledyne tank included in the AFVTV study. GDLS's design was unconventional with the powerpack mounted in the front, and an externally mounted cannon. The crew was located in the turret basket below the hull line. Three of the vehicles proposed had autoloaders, while Hägglunds did not. Although the Army did not require that proposals be tracked or wheeled, all four proposals were tracked.
Close combat vehicle light becomes the AGS FMC began developing the CCVL as a private venture in 1983. The vehicle was designed from the outset to meet the Army's as-yet unfunded AGS requirement. FMC built two mock-ups. The first was a front-engine model utilizing a diesel engine. The second was a rear-engine model with a diesel engine and featuring more armor. In 1984, FMC validated the feasibility of pairing the 105 mm gun with a light chassis by test firing a 105 mm gun mounted on an
M548. The first prototype CCVL was completed in August 1985 and debuted at the meeting of the
Association of the United States Army in October. The CCVL was demonstrated at Fort Bragg, North Carolina, in 1987. FMC subsequently ended the marketing of the vehicle and disassembled the prototype. A prototype participated in an AGS "rodeo" with other prospective contractors held in July 1990 at Fort Bragg, North Carolina. This was the only submitted vehicle that was considered complete. FMC claimed it could achieve C-130 airdroppability and so such a requirement was written into FMC's contract. FMC made several weight-saving changes to the design, particularly the pallets, in order to meet the C-130's weight limit. In a December 1993 report, the
Defense Department Inspector General (IG) cautioned that the AGS would be too heavy for
low-velocity airdrop (LVAD). The IG recommended canceling 58 systems meant for the
XVIII Airborne Corps if the Army could not demonstrate LVAD from a C-130. The Pentagon concurred that no production could begin until the Army met this requirement. The IG's concerns were put to rest in October 1994, when the service successfully airdropped an AGS from a C-130 at an altitude of . Citing cuts in the service's procurement budget, in 1993, the Army reduced its planned AGS order from 300 to 233. By November the Army had successfully overhauled the program. By reclassifying the preproduction prototypes as production models, the Army was able to cut two years off the time until full-scale production. The Army had by then settled on an acquisition target of 237 vehicles. Of these, 123 would go to the 2nd Armored Cavalry Regiment, 58 to the 82nd Airborne Division, and 56 to reserves and training bases. The last 169 AGS systems, to be produced from 1998 to 2002, were to be built without the weight-saving modifications of those destined for the 82nd, which was the only unit that required an airdroppable AGS system. The AGS's budget was zeroed and the production schedule slipped by one year in Congress's FY1995 budget due to program cost growth. Six prototypes were built under the designation XM8. The first of these was rolled out at the United Defense (created by a merger of FMC and
BMY) facility in San Jose, California, in April 1994, and arrived at
Fort Knox, Kentucky, in April 1995. The last of these was delivered in May. United Defense provided five XM8 AGS systems to the service's
Operational Test Command, which put the vehicle through five months of testing at
Fort Pickett, Virginia. Another prototype underwent survivability testing at
Aberdeen Proving Ground, Maryland.
Cancelation In 1995, the Army explored inactivating the 2nd ACR, which would reduce the Army's buy to just the 80 AGS systems destined for the 82nd Airborne. In May 1995, the
Army National Guard expressed interest in procuring the AGS for the
38th Infantry Division,
35th Infantry Division and
34th Infantry Division to help bridge the looming capability gap should the 2nd ACR be eliminated. This proposal was rejected by the service. Army Chief of Staff
Gordon R. Sullivan, the AGS's most influential advocate at the Pentagon, retired in June 1995. In October 1995, the Army
type classified the XM8 as the M8 armored gun system. the President's FY1996 budget request allotted the Department of Defense (DoD) the lowest procurement budget level since 1950. The AGS was one of several systems that did not fare well in an Army review of anti-armor weapons then under development. Responding to budget cuts anticipated in the period FY98–03, in 1996 the Army adopted a new policy: Instead of distributing small cuts throughout many projects, entire programs would be canceled. Army Chief of Staff
Dennis Reimer canceled the AGS in January 1996. Many officials felt blindsided by the Army's decision to kill the AGS. The Army's decision to cancel the AGS went without a formal announcement but was soon leaked to the press. This displeased some lawmakers including Senate Armed Services Committee chairman
Strom Thurmond, who privately expressed irritation to
Defense Secretary William J. Perry about having learned of the cancelation through media reports. However, in February the DoD's
Joint Requirements Oversight Council (JROC) endorsed the Army's decision. The Army considered a variety of plans to "heavy up" the 2nd ACR. The service added heavy armor to the 2nd ACR and requested funding to purchase
Apache helicopters. In the 82nd Airborne, the Army also planned to introduce the
EFOGM missile and considered more widely fielding the Javelin missile. Funding for EFOGM was deleted in 1998. The Army also considered the
MGM-166 LOSAT missile, now mounted on a Humvee rather than the originally planned AGS, as another platform offering similar capabilities for the 82nd Airborne. However, this program was canceled in FY2005. According to Reimer, the lack of a C-130-deliverable tank was made somewhat more acceptable by the introduction of an increasing number of larger C-17's. In place of the Sheridan in the 82nd Airborne, the Army stood up an Immediate Ready Company of
Bradley Fighting Vehicles and
M1A1 Abrams tanks from the
3rd Infantry Division which were to be attached to the 82nd.
Milestones and schedule A Milestone I/II review was completed in May 1992. The engineering and manufacturing development contract was awarded to FMC in June 1992 for a ballistic structure, six test vehicles, and technical data. A
critical design review was completed in September 1993. Six pre-production prototypes underwent technical testing in FY94–95. Early User Test and Experimentation was completed in June 1995 and was highlighted by a successful LVAD of a prototype AGS. Live fire testing and initial operational test and evaluation were scheduled to be conducted in FY96. A full-rate production decision was scheduled for March 1997 (Milestone III).
Proposed revivals and exports In 1998, the Senate Armed Services Committee proposed using the M8 AGS as a surrogate vehicle to evaluate "strike force experimentation activities" in the
2nd Cavalry Regiment. In October 1999, Army Chief of Staff
Eric Shinseki laid out his vision for a lighter, more transportable force. The Army began the
Interim Armored Vehicle (IAV) program to implement Shinseki's concept. United Defense provided three AGSs oufitted with levels I, II and III armor for a platform performance demonstration from December 1999 to January 2000. One of these systems was equipped with improved
forward-looking infrared. UDLP protested the award, alleging that the Army disregarded its own timeline requirements and that the requirements were unfairly biased for wheeled vehicles. The General Accounting Office denied UDLP's protest in April 2001. In March 2004, at the 82nd Airborne Division's request, the Army approved the transfer of four production vehicles from United Defense's facility in
Pennsylvania to Fort Bragg, North Carolina. An air-drop test of a Stryker weighted to simulate the load of the MGS was conducted in August. Around the same time, the Army identified issues with the airworthiness of the MGS, among the heavier of the
Stryker family. Still more pervasive problems persisted with the autoloader. While this decision was on hold, Congressman
Robin Hayes expressed frustration that the AGS had not been fielded, and called on the DoD to act swiftly to resolve the delay. In January 2005, the Army said it had ruled out fielding the AGS, saying the system lacked spare parts that would be required to maintain the vehicle for any significant length of time. The Army also doubled down on its commitment to fielding the MGS, which it said it could begin fielding in summer 2006. United Defense sought overseas customers without success. In 1994 United Defense partnered with
Rheinmetall to market the AGS to NATO allies. Taiwan was interested in acquiring as many as 700 of the system, which would be produced domestically. That year the
U.S. State Department authorized the sale of just as many to Taiwan and United Defense agreed to co-production with Hwa Fong Industries conditional on the selection of the vehicle by Taiwan. United Defense manufactured a demonstrator vehicle which it shipped to Taiwan . United Defense presented a version of the AGS without the autoloader. This was a cost-saving measure to allay Taiwan's concerns about the cost of the system. In 1996
FMC-Nurol and United Defense teamed to market the AGS to Turkey, which had a requirement for 200 systems. This bid was said to be a longshot as Turkey's requirement was for a
main battle tank in the range. In 2017, the Army formalized its requirements with a request for proposals. The MPF was defined as an air-transportable light tank to assist infantry brigades in forced entry operations. The Army sought to buy 504 MPF systems. Requirements called for a tracked vehicle armed with a 105 mm or 120 mm caliber cannon, which would not need to be air-droppable.
BAE Systems (which bought United Defense in 2005) entered a modernized AGS into the MPF competition. In 2018, the Army selected bids from GDLS and BAE to build 12 prototypes each. BAE began delivering the prototype vehicles to the Army in December 2020, The Army's evaluation of BAE and General Dynamics prototypes at Fort Bragg, North Carolina, continued through August. In February 2022, BAE was eliminated from the competition due to noncompliance issues, leaving the
General Dynamics Griffin as the only remaining MPF entry. In June 2022, the Army selected the Griffin as the winner of the MPF competition. == Design ==