AIE-486H machine gun

The AIE-486H Heavy Machine Gun or HMG is a United Nations Space Command ground weapon effective against infantry and vehicles.

Overview
The AIE-486H Heavy Machine Gun is a standard heavy weapon in use by the UNSC for offensive and defensive purposes. It seems to have replaced the UNSC's M247 GP Machine Gun as the standard UNSC machine gun turret. For defensive purposes it can be mounted on a tripod but when used for assault it can be detached from its tripod by a SPARTAN-II's brute force. In its unmounted form, while mobile, it has a limited ammunition capacity of 200 rounds and takes about a second to "spin up" before reaching its highest rate of fire. When the player picks up this weapon, they still keep their two other weapons. However, they must drop the HMG before using their other weapons.

The label of "heavy machine gun" most likely places this weapon in a category above 7.62mm ammunition. Due to the triple rotating barrels, as seen on the standard version of the Warthog LRV's M41 LAAG, the AIE-486H HMG may very well use 12.7mm x 99 (.50BMG) cartridges, although this is unconfirmed. Adding to the confusion, the feed chute of the weapon does not appear large enough to accomidate .50BMG cartridges.

Operation
The mounted turret is capable of fully automatic fire and has extreme defensive value as a mass generator of suppressive fire. However, the user's rate of elevation is low, there is a maximum angle of fire, and the user is stationary, exposed, and unable to react quickly to close-range scenarios. It has an infinite ammo capacity while stationary.

Once on it, a SPARTAN-II can detach the turret and use it as a man-portable weapon (done by pressing B). Once detached, the player will appear in a third-person view. The player also becomes slower due to the weapon's weight. While wielding the gun in its standalone form (unmounted), you can't run or turn around quickly, nor can you melee or use grenades. If you are standing in one point you can aim slightly to either side before the Spartan adjusts his feet.

Pulling the right trigger (on the controller) once will cause the gun to fire two rounds at a moderate rate, while when you hold it down it builds up its rate of fire to a higher rate. It slowly climbs during automatic fire like the SMG, but its recoil is made lighter by the gun's weight. The gun cannot overheat like most miniguns in other games.

Trivia

 * The AIE-486H Heavy Machine Gun, belonging to a new class of weapons known as "Support Weapons." It is one of the four current third-person view weapons. The other known weapons are the M7057 Defoliant Projector, the Missile Pod and the Plasma Cannon.
 * In the third-person view picture to the right, the HUD says that the secondary weapon is a Spiker. It's actually an Assault Rifle on the back of the Spartan. This is because you do not lose the 2 weapons you were carrying before obtaining the turret. Once you drop the turret, your primary weapon will be the Spiker and your secondary will be the Assault Rifle.
 * In the Halo 3 Beta, the AIE-468H HMG spawns on Valhalla by territory 2 and above the gate on High Ground.
 * Like the M41 LAAG, the AIE-486H bears a striking resemblance to the GAU-19/A machine gun used by the United States military. Even more so in fact since the GAU-19 and AIE-486H both share the same distinctive flash hider over the muzzle, whereas the M41 does not.