Technology & Combat Characteristics
The RGM-79 GM was a mass-produced mobile suit based on the RX-78-2 Gundam. Its basic frame was easily adaptable to modifications into mission-specific GM models, and had a fairly high level of mobility for the time, both on Earth and in space. It had a maximum acceleration of 0.94 G in space, which was better than the Zaku and even the Gundam. On Earth's surface, the GM was also faster than the Zaku II. The armor of the GM was made from Titanium Alloy, a sturdy metal that could be refined more quickly and easily than the Gundam's Luna Titanium Alloy. Although Titanium Alloy is less durable than Luna Titanium Alloy, it is slightly lighter, which reduced the GM's overall mass compared to the Gundam's while still being superior to the Zaku II's super-high tensile steel armor.
The GM was primarily armed with a beam spray gun, a less powerful version of the Gundam's beam rifle that could still destroy mobile suits in a single shot. Early in production, the beam spray gun had yet to be mass-produced so most GMs were equipped with various machine guns. These machine guns continued to be used by the GMs later, and the machine could also use the Gundam's beam rifle when required. It could also use a mass production version of the Gundam's Hyper Bazooka for heavier firepower. For close combat, the GM was armed with a beam saber and a shield similar to those used by the Gundam. Commander units sometimes featured a second beam saber. Lastly, the GM had a pair of head-mounted 60mm vulcan guns for intercepting missiles or stopping enemy units from closing in.
History
At the onset of the One Year War, the Earth Federation did not take the mobile suit threat seriously- this was until the Principality of Zeon's military completely outmaneuvered and decimated the Earth Federation Space Force with their MS-06 Zaku II. As Zeon forces laid siege on Earth, the Federation developed several prototype mobile suits, the most notable being the RX-78-2 Gundam, from which emerged the Earth Federation's first mass-production mobile suit: the RGM-79 GM. Faster and more agile than the Zaku II both in space and on Earth, the GM would serve as the Federation's primary mobile suit throughout the war, and would later become the basis for the Earth Federation's mass production mobile suits for over fifteen years.
To compensate for Zeon initially being more experienced in mobile suit warfare, the Federation started with a 'quantity over quality' approach. By the time of the GM's true introduction at the Battle of Jaburo, Zeon had already began production of the MS-09B Dom, a mobile suit that performed slightly better than the GM, but was not appreciably more survivable or deadlier. When the war went back into space, the GM actually outperformed the MS-09R Rick Doms in most ways and were outperformed later by the MS-14 Gelgoogs; unfortunately for Zeon, the Rick Dom would be produced in too few numbers and the Gelgoog would not be deployed until the last two weeks of the war.
By the time the Gelgoog entered service, most Zeon pilots were fresh recruits who were up against a superior number of battle-hardened Federation counterparts, a situation that also plagued the surviving Zaku IIs and even the MS-05B Zaku Is that were forced to soldier on due to the scarcity of new mobile suits. It was then that the Federation's victory became guaranteed.
The GM marked the beginning of the RGM series that remained the mainstay of the Federation's mass production mobile suits until the end of the Federation itself. The GM line was first established through the [[RGM-79［E］ GM Early Type|RGM-79[E] GM Early Type]], a prototype version that would set the basics for the GM. The basic GM frame would later be updated and upgraded into the RMS-179 GM II during the mid-UC 0080s and would become one of the most heavily modified mobile suits, spawning many variants until finally being superseded by the RGM-89 Jegan in the UC 0090s.