This gundam paper model is a SD RX-77-2 Guncannon, the second mobile suit design model that stemmed from the Earth Federation's "Vinison Project" or "V Project" in the Mobile Suit Gundam anime, the papercraft is created by June.
The Guncannon was a step up from the RX-75-4 Guntank; while the Guntank was more "tank" than mobile suit, the Guncannon was a true mobile suit with limbs. However, it did share the Guntank's Core Block System, using the same FF-X7 Core Fighter. It is based on the data of the RXM-1 prototype bipedal robot.
The first Guncannon was the prototype RX-77-1A Guncannon A, which had poor mobility due to its heavy armor. The second version, RX-77-2 Guncannon, corrected this problem. As defensive weapons, it mounted two 60mm Vulcan guns in the head. However, the Guncannon's primary weapons were the twin 240mm cannons mounted on the shoulders, which were used for the mobile suit's design purpose: mid-range support. The Guncannon was also the first mobile suit used by the Earth Federal Forces capable of firing a beam rifle.
The Guncannon was less mobile but more heavily armored than its cousin, the RX-78-2 Gundam. Unfortunately, the extra armor provided no additional protection against beam weapons, and powerful conventional weapons were capable of causing severe damage. It also lacked any sort of melee weapon, making it helpless when an enemy mobile suit got too close. Also, its 240mm cannons only held 20 rounds per cannon, meaning the pilot had to learn how to conserve cannon ammunition and use it wisely.
Where the Guntank was designed as a long range support unit, the Guncannon is the mid range support for the Gundam. Like the RGM-79 GM, the Guncannon was also manufactured at Jaburo. [Source: wikia]
You can download this papercraft template here: SD RX-77-2 Guncannon Free Gundam Papercraft Download [Box] [Gavitex]