M99 chaingun

The M99 Light Anti-Aircraft Gun, is a United Space Command Armed services vehicle-mounted machine gun. It is used as the primary armament of a standard MR2 Chaingun Buffalo, as well as the TODT RAPTAR.

Design details

The M99 LAAG was designed by the Mars Corps Armory specifically for use as a vehicle-mounted anti-aircraft weapon. It features three parallel barrels with a rate of fire of 500 rounds per minute. The gun is powered by an electric motor, allowing for continuous operation without the need for manual reloading. One of the key design features of the M99 is its linkless belt feed system. This means that the ammunition is not linked together in a chain, but rather fed directly into the gun from two separate 1,000-round belts. This design allows for faster and more efficient reloading and reduces the risk of jamming.
The weapon's turret has a traverse rate of 100 degrees per second, making it highly effective against fast-moving aerial targets. The elevation rate is also impressive at 60 degrees per second, allowing for quick adjustments to hit targets at different altitudes. However, sustained firing from the M99 can result in significant recoil that negatively impacts accuracy at long range. As such, it is primarily used for short to medium-range engagements.
In addition to its standard variant, there is also an extended version known as the M99 Extended Light Anti-Aircraft Gun. This version features four barrels instead of three and is capable of firing depleted uranium-containing pressurized atmosphere rounds. These specialized rounds are designed to penetrate heavily armored targets and are particularly effective against larger aircraft or ground vehicles.

Ammunition

The ammunition used for the M99 LAAG is the 12.7×99mm armor-piercing round. This round is significantly larger and more powerful than the standard 7.62×51mm rounds used in other USC weapons, such as the A5 series of assault rifles. The 12.7×99mm round has a muzzle velocity of 2,800 feet per second (853.44 meters per second) and an effective range of 1,000 yards. It is designed to penetrate heavily armored targets, making it ideal for use against aircraft and ground vehicles.
The rounds are fed into the gun via two separate 1,000-round belts, which are linked together by a linkless feed system. This design allows for faster and more efficient reloading, as well as reducing the risk of jamming. In addition to its standard armor-piercing rounds, an extended version of the M99 LAAG can also fire specialized depleted uranium-containing pressurized atmosphere (DU-PA) rounds. These rounds are capable of penetrating even thicker armor and are particularly effective against larger aircraft or ground vehicles.
The M99 LAAG also has a secondary ammunition type known as high-explosive incendiary (HEI). These rounds are designed to explode upon impact, causing damage to surrounding targets and potentially igniting fuel or munitions on enemy vehicles.

Production overview

Manufacturer

Mars Corps Armory

Model series

M99

Type

Manned-Light anti-aircraft gun

Specifications

Mass

31 lb (14.1 kg)

Length

48 in (1,219.2 mm)

Barrel length

24 in (609.6 mm)

Ammunition type

12.7×99mm armor penetrating rounds

Feed system

two-1,000-round belts

Operation

Electrically-powered, belt-feed

Muzzle velocity

2,800 ft/s (853.44 m/s)

Effective firing range

1,000 yd

Maximum firing range

2,500 yd