AMP machine gun
|Behind the scenes|
The GAU-90 is a massive, 30mm hip-fired autocannon. It can fire up to 250 high explosive, armor-piercing, or incendiary rounds per minute and has a large bayonet slung under the barrel support.
The GAU-90's savage recoil demands that the AMP suit operator devotes both hands to controlling the weapon. It also requires increased servicing of the AMP unit's actuator assemblies, particularly in the right shoulder and elbow.
Although primarily designed as a ground attack anti-vehicle/anti-armor weapon, the gun can be used for slower moving air targets and in anti-personnel roles. This versatility of use combined with the rugged frame make it an easy choice for deployment in the harsh Pandoran environment.
The weapon is reminiscent of the mid-20th century Browning "Ma Deuce" .50 caliber machine gun in its simplicity, lacking advanced optical, laser or other aiming/tracking assistance.
The gun can be slung using an over the-shoulder rifle-sling to free the hands for other tasks. The ammunition feed link remains connected while slung.
Only those AMP units with SecOps designation have access to this weapon, and targeting computer and ammunition bin/feed link installed. AMP units fielded by the mining and other non-security base personnel lack the weapon system and the training to use it effectively.
The GAU-90 eschews modern caseless ammunition, instead relying on tried-and-true cased rounds. While this reduces the effective weight of ammunition the AMP suit can carry, the reliability of cased ammunition is much valued in the corrosive Pandoran atmosphere. The simpler propellant used in cased rounds offers the advantage of greater shelf life and stability compared to caseless rounds.
The hot brass casings ejected from the weapon weigh 2 lbs (0.91 kg) each and often land up to 30 ft (9.14 m) from the weapon, which can prove problematic for nearby unarmored ground troops.
It is used as a "rifle" by the Amplified Mobility Platforms. Range and projectile ballistics are reduced due to Pandora having a denser atmosphere than Earth. However, given the often point-defense encounter profile, this is not seen as a serious disadvantage.
Most SecOps AMP drivers prefer the standard allocation of 300x 30mm AP rounds for maximum stopping power and minimal collateral or "splash" damage. Incendiary and high explosive rounds tend to be favored by ex-special forces drivers.