The MGS program emerged after the 1996 cancelation of the Army's M8 armored gun system, the service's planned replacement for the M551 Sheridan light tank.

[citation needed] This led to the development of a new armored fighting vehicle designed for lower-intensity combat, rather than large-scale battle.

[11] The General Dynamics mobile gun system originated from the Canadian armoured combat vehicle requirement.

[14] In October 1999, U.S. Army Chief of Staff Eric Shinseki laid out his vision for a lighter, more transportable force.

the AGS was also intended to be used in the anti-armor role, whereas primary targets for the MGS included bunkers, buildings, weapon positions and troops.

[16] A team of GM Defense of Canada and GDLS submitted a variant of the LPT assault gun to meet the MGS requirement.

[21][22] GM–GDLS was forced to suspend work on the IAV while the Government Accounting Office evaluated UDLP's protest of the award.

In its protest, UDLP alleged that the Army had known about the schedule slippage before awarding the contract, and unfairly disregarded this in their decision making.

[25] In August, the Army conducted an air-drop test of a Stryker M1132 engineer squad vehicle weighted to simulate the load of the MGS.

[26] In January 2005, the Army said it had ruled out fielding the AGS, saying the system lacked a sufficient inventory of spare parts that would be required to maintain the vehicle.

[27] In October 2004, the Pentagon approved limited low-rate production of the MGS after a Defense Acquisition Board review.

[5] In late 2013, the U.S. Army began seeking to reintroduce an airdroppable mobile airborne protected firepower platform to provide fire support for air assault forces, a capability that had been absent since the retirement of the Sheridan in 1997.

General Dynamics initially considered modifying the wheeled Stryker MGS to meet the Mobile Protected Firepower (MPF) program requirement,[35][36] but the company instead entered a variant of the Griffin light tank.

It was more efficient to eliminate the platform and focus on firepower improvements such as equipping Strykers with 30 mm cannons (M1296 Dragoon) and CROWS-J mounts, providing better distributed lethality capabilities that will not be lost from removing the MGS.

[40] The MGS commander and gunner are located in the turret basket, which provides the crew some separation from the ammunition in the event of an explosion.

According to a Government Accounting Office report released in May 2001, the Army had expressed doubt that this arrangement would provide "any protection from secondary explosions and fires from the main gun ammunition.

"[40] The MGS's low profile turret has a small silhouette, is stabilized and mounts a 105mm M68A1E4 rifled cannon with a fume extractor and an autoloader.

[41] The MGS can store 18 rounds of main gun ammunition: 8 in the autoloader's carousel and 10 in a replenisher located at the rear of the vehicle.

[48] By 2000, the Army found its existing ammunition stockpile of 105 mm rounds to be in poor condition, with more than half determined to be either unusable or obsolete.

The Army planned to authorize 32 mobile gun systems to a Stryker Brigade Combat Team (BCT).