Autocannons

Name	Type	Scale	Automated	Fire Control	Caliber	Space Range	Atmosphere Range	Damage
M638	Autocannon	Walker	N/A	1D	20mm	1-3/8/15	10-300/800/1,500m	3D
M655	Autocannon	Walker	N/A	1D	20mm	1-3/8/15	10-300/800/1,500m	3D
M995	Autocannon	Walker	N/A	1D	30mm	1-3/8/15	10-300/800/1,500m	3D+1
M1024	Autocannon	Walker	N/A	1D	30mm	1-3/8/15	10-300/800/1,500m	3D+1
GUA-23/A	Autocannon	Walker	N/A	1D	30mm	1-3/8/15	10-300/800/1,500m	3D+1
GUA-23/AW	Autocannon	Walker	N/A	1D	30mm	1-3/8/15	10-300/800/1,500m	3D+1
M1075	Autocannon	Walker	N/A	1D	35mm	1-3/8/15	10-300/800/1,500m	3D+2
M8545	Autocannon	Walker	Starship Gunnery: 4D	1D	40mm	1-3/8/15	10-300/800/1,500m	3D+2
AAA Helix Gun	Autocannon	Starfighter	Starship Gunnery: 4D	1D	50mm	1-3/8/15	10-300/800/1,500m	2D
M910	Autocannon	Starfighter	Starship Gunnery: 4D	1D	50mm	1-3/8/15	10-300/800/1,500m	2D
GAU/53	Autocannon	Starfighter	N/A	1D	70mm	1-3/8/15	10-300/800/1,500m	2D+1
M370	Autocannon	Starfighter	N/A	1D	70mm	1-3/8/15	10-300/800/1,500m	2D+1
Rotary Cannon	Autocannon	Starfighter	N/A	1D	110mm	1-3/8/15	10-300/800/1,500m	3D
Ventral Gun	Autocannon	Starfighter	N/A	1D	120mm	1-3/8/15	10-300/800/1,500m	3D+1

M638 Autocannon

The M638 Autocannon is used as both an anti-personnel and anti-armor weapon, and is exclusively mounted on the UH-144 Falcon. It fires explosive rounds that can wound targets close to their blast radius and cause heavy damage to armored targets as well. It is effective against both infantry and stationary gun emplacements such as the Shade turret, and is powerful enough to allow a Falcon to hold its own in a dogfight against multiple Banshees. Sustained fire from an M638 is even capable of destroying Phantom dropships. The autocannon fires in 5 round bursts, and only needs 3 or 4 to eliminate a Banshee on most difficulties.

Strangely, for a large caliber weapon with a high rate of fire, it does not overheat, even after minutes of continuous firing. This is likely due to the fact that it only fires in bursts, which allows it to dissipate heat in between shots.

M655 Heavy Machine Gun/Anti-Materiel

The M655 Heavy Machine Gun/Anti-Matériel is a 20mm HMG used by the UNSC Defence Force. Some versions of the HRUNTING/YGGDRASIL Mark IX Armor Defense System are armed with an M655 as well as an M5920 surface-to-surface missile launcher.

M995 ASW/AC 30mm MLA

The M995 ASW/AC 30mm MLA is a 30mm autocannon mounted on the B-65 Suborbital Long-Range Bomber.

M1024 ASW/AC 30mm ALA Cannon

The M1024 ASW/AC 30mm ALA Cannon is a UNSC projectile weapons mounted on single ship starfighters. A pair of M1024 ASW/AC 30mm ALA Cannons are mounted on the YSS1000, near the cockpit, as its main armament. It is noticeable that few shots destroy a Space Banshee and take down the shields of a Seraph.

A pair of M1024 30mm Cannons mounted on a Sabre can take down a Seraph's shields in a few shots which is odd considering the 50mm MLA point defense guns mounted on larger UNSC vessels take 150 rounds to take down a Seraph's shields.

GUA-23/A Heavy Autocannon

The GUA-23/ Heavy Autocannon is a UNSC heavy weapon commonly mounted on the AV-14 Attack VTOL. These heavy machine guns provide the Hornet sufficient firepower for countering Covenant Banshees and ground forces.

GUA-23/AW/Linkless Feed Autocannon

The GUA-23/AW/Linkless Feed Autocannon is a weapon in service within the UNSC Marine Corps, mounted on AV-22 Sparrowhawks and AC-220 Gunships. These autocannons fire 30mm rounds which can be used to engage a number of enemy units of various types, ranging from infantry, to armored vehicles, to aircraft.

M1075 ASW/AC 35mm MLA

The M1075 ASW/AC 35mm MLA is a 35mm autocannon. Two of these are mounted on the F-41 Broadsword-class XMSF.

M8545 ASW/AC MLA

The M8545 ASW/AC 40mm MLA is an autocannon on the Winter-class light prowler.

AAA Helix Gun

The AAA Helix Gun is a UNSC starship-mounted point defense weapon. The autocannon can be found affixed to human capital ships during the Insurrection and the Human-Covenant war as late as the Battle of Psi Serpentis in 2543.

M910 PDG

The Point-defense gun is a United Nations Space Command starship-mounted weapon that fires 50mm high-explosive projectiles

GAU/53 70mm MBHRC Autocannon

The GAU/53 70mm MBHRC Autocannon is a triple barreled, anti-personnel and anti-vehicle weapon used by the United Nations Space Command. There are two mounted on the nose of the D79H-TC Pelican and one mounted on its gunship variant, the G79H-TC/MA Pelican.

M370 Autocannon

The M370 autocannon is an anti-personnel/anti-vehicle weapon mounted below the nose of most D77-TC Pelican dropships. The weapon fires 70mm depleted uranium slugs and is sometimes twin-linked with another such weapon, doubling its firepower. The gun is linked to the movements of the pilot's head, which allows for very short delays between spotting enemies and firing; the turret can rotate up to 120 degrees to wherever the pilot is looking. The turret can also be operated by a copilot, or manually by a gunner. The weapon seemingly replaced the 40mm chain gun, that was common prior to 2525.

Rotary Cannon

The 110mm rotary cannon is a projectile weapons equipped to the GA-TL1 Longsword-class Interceptor, essentially a gatling-style cannon firing large 110mm shells and used to engage enemy fighters or starships as well as ground target's if needed.

Ventral Gun

The 120mm ventral gun is a weapon mounted in pairs to the underside of the UNSC GA-TL1 Longsword-class Interceptor. It possesses at least a 90 degree swivel, and is able to be retracted into the hull. The weapon's shells are of a higher caliber than the Longsword's main weapon, the 110mm Rotary cannon, and presumably do more damage.

During the capture of the Ascendant Justice by UNSC survivors of the Battle of Installation 04, a Longsword's 120mm Ventral guns were used to clear one of the vessel's hangars of a "legion" of Unggoy. The shells cut through unshielded fighters, fuel pods, and the Covenant defenders with ease.

UNSC Autocannons