「RGC-80プロトタイプ　ジム・キャノン　(ジム・キャノン1号機)」
RGC-80 PROTOTYPE GM CANNON (GM CANNON Unit.1)

Manufacturer: Earth Federation Forces
Height: 18.0m
Weight: 48.9t
Development Location: Jaburo
Armament: unknown

BACKGROUND:

Given the performance characteristics of the already completed RX-77 Guncannon as a mid-range support unit, it was expected to be mass produced as is. However, with the plan to simplify the multipurpose mobile suits of the core RX project it became necessary to further simplify the 77 model.

To mass produce it, the Federation Forces planned to retain the core fighter’s functionality as the core block to serve as an escape system, while the upper body would carry the cannon equipment to provide mid-range support. Shortly following these orders, the RGM-80 prototype Unit 1 rolled out at Jaburo in October 0079 equipped with 360mm cannons on both shoulders. The completed Unit 1 retained the Type 77 head, while the twin 360mm cannons were installed on the body of the RGM-79 with a modified back block structure.

Although it has low recoil, the suit experienced problems with stability and weight balance when firing the same cannons at the Type 77. In order to achieve the same firing performance as the Guncannon, modification work was conducted focusing on the 360mm cannons.

FEDERATION SURVEY SERVICE REPORT:

The above image is of the RGC-80 GM Cannon Unit 1 conducting a test fire of it’s 360mm cannons at the Earth Federation’s firing range. Because the coloring of the RGC-80 is the same color base red as the RX-77, the photography date and time are assumed to be the first half of October 0079 soon after it’s rollout. Unit 1 was constructed at Jaburo, so the photoshoot location is assumed to be a test firing range in South America. However, the Federation Forces had more than one practice firing range in both North and South America in 0079 so determining where exactly based on this picture is difficult.

While it is said that there was a problem with balance during the firing of the cannons, based on this picture you wouldn’t feel it. The picture seems to have been taken on the same day as this is the only cut, so it’s difficult to determine the initial performance of Unit 1. Perhaps it is because the required performance of the Federation Forces was high that the balance problem during shooting was given a closer look. Based on this image, confirmation cannot be made of the instability when shooting because the demands of the Federation Forces when the RGC-80 GM Cannon is developed were not clarified.

The white mobile suit that is standing at the right of the image is a MS-06 Zaku II that was captured by the Federation Forces. Records indicate that during the war, numerous Zeon mobile suits were captured by the Federation Forces and that analysis on the Zeon’s war potential were conducted. Records left behind indicated mock battle were carried out with the RGM-79, denoting it was an operational mobile suit. It’s possible that this Zaku II was also a machine used for data collection on the firing range.