Technology & Combat Characteristics
A further development of the RX-77-2 Guncannon, the RX-77-3 Guncannon Heavy Custom fixed some of its predecessor's issues and had better operational capability. Compared to the Guncannon, the Guncannon Heavy Custom had lower recoil when firing its 240mm Cannons. Furthermore, the cannons' rate of fire and ammunition feed system were improved, leading to higher offensive power. It also has enhanced armor for better defense, carried a heavier payload, and its backpack's propulsion system has a higher thrust output to offset the added weight and to improve mobility.
Some of these improvements were made to meet the Earth Federation Forces' demands; they wanted the Guncannon Heavy Custom to be capable of solo combat, as well as be able to form a homogeneous mobile suit team for group combat. There were also considerations to deploy such a team of Guncannon Heavy Customs alongside other mobile suit teams for cooperative battle. The performance of the completed Guncannon Heavy Custom was satisfactory, but the Earth Federation Forces ordered the development department to conduct further research as there were issues, such as its mobility, which could be improved upon.
To solve the recoil and balance issue completely, some test units later had their cannons replaced with a beam cannon. As the Guncannon Heavy Custom only received a limited production run, it was thus an uncommon machine. During the Gryps War years later, units stationed in Jaburo were outfitted with panoramic cockpit monitor, linear seat, a new color scheme and used the same beam rifle as the RMS-179 GM II.
- 60mm Vulcan Gun
- A pair of shell-firing armament built into the head. Low offensive power, only used to restrict enemy movement, and lay down a wall of suppressive fire due to their rapid fire capability.
- 240mm Cannon
- Like the original Guncannon, the Guncannon Heavy Custom's main weapon is a pair of shoulder-mounted 240mm cannons. However, the Guncannon Heavy Custom's cannons have better offensive power due to a higher rate of fire and a better ammunition feed system. The recoil during firing has also been reduced, and although this issue is not completely eliminated, it does not cause much problem during practical use.
- Beam Cannon
- Instead of the shoulder mounted cannons, the Guncannon Heavy Custom can be fitted with the same beam cannon and targeting unit as the RX-77-4 Guncannon II.
- XBR-M-79a Beam Rifle
- The Guncannon Heavy Custom can use the same beam rifle as the RX-77-2 Guncannon. This particular beam rifle is specialized for sniping. Compared to the beam rifle used by the RX-78-2 Gundam, it was harder to use but had higher accuracy and longer range. It is said to have a range of around 30km.
- BOWA·BR-S-85-C2 Beam Rifle
- The same weapon as used by RMS-179 GM II, it has a power rating of 1.9 MW and is powered by a built-in energy CAP system. This beam rifle was used by the Guncannon Heavy Customs stationed in Jaburo during the Gryps War.
- Hand Grenade
- The Guncannon Heavy Custom has an unknown number of hand grenades stored in a rack on its left side armor. Various types of hand grenades can be stored.
During the early part of the Gryps War in UC 0087, at least one Guncannon Heavy Custom was known to have participated in the defense of the Earth Federation's Jaburo base. In the Mobile Suit Zeta Gundam Define manga, Kai Shiden would use a Guncannon Heavy Custom he found in a MS hangar to escape from Jaburo base.
- RX-77-3B "Bear Carrier"
- RX-77-3D Guncannon Heavy Type D
FA-78-2 Heavy Gundam | RGM-79L GM Light Armor | RX-77-3 Guncannon Heavy Arms Type | RX-77-4 Guncannon II | RX-78-3 Gundam "G-3" | TGM-79 GM Trainer
|Aircraft / Spacecraft|
Corvette Booster | Guncarry | Lightliner
|Principality of Zeon|
MS-06R-2 Zaku II High Mobility Type | MS-10 Pezun Dowadge | MS-11 Act Zaku | MS-12 Gigan | MS-13 Gasshia | MS-17 Galbaldy α
|Aircraft / Spacecraft|