M276 Anti-Air G-Gun

The M276 Anti-Air G-Gun was a Western-aligned anti-aircraft turret that was in service since at least late 1974.

Background and features
Due to its high firing angle, the M276 Anti-Air G-Gun was considered optimal in mountainous ranges. As such, firing all of its rounds at once was considered a terrifying display of power.

History
The M276 Anti-Air G-Gun was in service since at least late 1974, being in service for the United States military. The United States Marine Corps had four stationed at the U.S. Naval Prison Facility in Cuba since at least late 1974.

Side Ops
Big Boss attempted to take out at least three of these weapons at the base, in order to allow the JCF-aligned MAGTF chopper to safely descend onto the base due to the base personnel going renegade via Cipher. However, by the time Big Boss arrived and sabotaged one, the base was already under high alert due to the mission being leaked.

The M276 Anti-Air G-Guns were present on the base when Big Boss arrived to rescue Chico and Paz.

The M276 Anti-Air G-Guns were present throughout the Angola-Zaire border region of Central Africa during the 1980s, namely being utilized to guard various high-priority bases such as the Nova Braga Airport and the mansion at Lufwa Valley. Venom Snake and Diamond Dogs stole several of these turrets during their operations in the region. In addition, both Diamond Dogs themselves and several rival outfits modeled after them had M276 Anti-Air G-Guns as well as their Soviet-based counterparts, the Zhizdra-45, dotting their Forward Operating Bases (and in the case of Diamond Dogs, their own primary base of operations).

Behind the scenes
The M276 Anti-Air G-Gun first appeared in Metal Gear Solid V: Ground Zeroes, but was unidentified until Metal Gear Solid V: The Phantom Pain. They appear in the "Ground Zeroes" mission, every Side Op, and the "Déjà Vu" Extra Op.

Appearances

 * Metal Gear Solid V: Ground Zeroes 
 * Metal Gear Solid V: The Phantom Pain