"RGM - 79SC Jim · Sniper Custom" is a custom type mobile suits developed based on "RGM - 79 Jim" for pilots with high fighting skill in the latter half of the one - year war. "RGM-79 Jim", the flagship mobile suits of the Earth Federation Army, compared with the base "RX-78-2 Gundam", because its importance was placed on productivity and operability, its performance was greatly inferior It was. Regarding its performance defects, a form supplemented by physical warfare called collective tactics was taken, but dissatisfaction was raised against specs that can not demonstrate their fighting ability from some highly skilled pilots. In order to listen to requests from such experienced pilots, it has led to the creation of aircraft considering fighting performance and artillery ability, addition of armor and reinforcement of beam weapons.
Renewal of the aircraft based on "RGM - 79 Jim" was done at Compaito (formerly Solomon) and Luna - to which the Earth Federation army collapsed. Arrange additional armor on the front of the fuselage, such as head visor and chest, to improve defense capability during proximity fighting. In order to improve mobility of the aircraft, a thruster of large thrust is placed in the backpack and an auxiliary thruster is placed in the leg. In strengthening the beam weapons, it was possible to improve the generator output and to carry more cooperative beam weapons. As fixed arms, a box type beam saber fixed to the right arm part, hand beam shot is arranged on the left foot. In addition, for some aircraft, R-4 type beam rifle with high sniper performance is also being offered. In addition, a latch that can fix regular arms such as bazooka, beam spray gun, etc. was added to the back of the waist, and it became an airframe that can be equipped according to the battle situation. These aircraft have been deployed in escort units of mother ship and special troops specialized in melee fighting, and they are also participating in the final battle of A · Baa · Ku. However, due to its high production cost, it is said that about 50 machines were produced.
Regarding the remodeling, although basic specifications are unified, it is said that there were various types of aircraft existed depending on demands of skilled pilots, detailed specifications are not constant. Furthermore, at the deployment destination, names and exclusive arms corresponding to the operational purpose such as "intercept" and "guard type" were given. Among them, it is said that the type used for long-distance shots that Francis Bachmeyer Lieutenant principal had chameleon's picture as personal marker is famous, and the name of "Sniper custom" is said to point to his aircraft There. It was also confirmed that some of the aircraft that survived after the one year war were deployed in the Gabbro garrison during the Grips war.