M247 machine gun

The M247 General Purpose Machine Gun (abbreviated M247 GPMG), colloquially known as the GP Machine Gun Turret, is a heavy weapon used extensively by the United Nations Space Command ground forces.

Design Details
The General Purpose Machine Gun, normally depicted as a stationary gun emplacement, is usually placed near defensive positions in and around UNSC bases and fortifications. It is capable of firing an incredible number of .30-caliber rounds. It is evidently chambered for the 7.62x51mm NATO standard cartridge, as "7.62x51mm" is printed on sides of the large, nearby ammunition crates The M247 turret has three variants found in Halo 2 and one variant in Halo Wars:
 * 1) Fixed - This variant of the turret has a slab of armor plating to protect the operator from incoming fire, and is used as a defensive weapon by the UNSC Marine Corps. In addition, it is the only variant available for use in multiplayer.
 * 2) Portable - The second variant is man-portable, equipped with a folding tripod or bipod for rapid relocation and setup in the field. To lighten the load, the protective plate is removed. This version is unavailable in multiplayer, and is incapable of being picked up or relocated whenever it appears in the campaign.
 * 3) Pelican-mounted - This variant is secured via a mount hanging from the ceiling of the Pelicans' rear compartment.
 * 4) Elephant-mounted - This variant is mounted on Elephants when upgraded. It will operate only when the Elephant is in lock-down mode and is quite effective against infantry and light air units.
 * 5) M247-TMMG (M247 Tank Mounted Machine Gun) - This variant is equipped on the Grizzly and Scorpion main battle tanks for anti-infantry combat.

Advantages
The M247 is a very effective weapon against enemy infantry and light vehicles. It is also far less visible in comparison to the Covenant's equivalent, the Shielded Plasma Cannon making it somewhat harder to spot. In addition, its tracer rounds are more difficult to spot compared to the searing, white-hot plasma bolts of the Shielded Plasma Cannon, and it has a much higher rate of fire. The M247 can also withstand a direct frontal hit from the main armament of a Wraith or the M68 Gauss Cannon, so long as the gunner has a high shield and health level. While the 7.62x51mm round it uses is effective against armor and flesh, unlike plasma-based weaponry it isn't particularly effective against shields. Despite this, the M247's high volume of fire makes it a highly desirable weapon.

Curiously, in-game, the location of impact of the M247 on a target does not affect the damage inflicted. Therefore, a target shot in the legs would take the same amount of damage then if he was shot in the chest. The M247 can take down enemy targets under sustained fire: a target that is unshielded can take only two or three rounds before dying, while a fully shielded target can survive seven or eight. A target with a fully charged overshield can take eighteen rounds before being killed, or three seconds. This is not a problem, as the high volume of fire will make short work of any foe.

Disadvantages
As is the case with the Shielded Plasma Cannon, the M247's gunner is extremely exposed to enemy fire and will invariably become a high-value target to be taken out. A single hit by a Rocket Launcher, a round from the Scorpion tank's main gun, or a well placed plasma grenade will destroy the turret and kill the gunner. In addition, the aforementioned hit from a Wraith or an M68 Gauss Cannon will also completely deplete the gunner's shields, leaving said individual vulnerable to a follow-up shot.

While it is useful against enemies in light vehicles, this is not a weapon to use when faced with enemy armor, as the .30 caliber rounds will have little effect on a Scorpion or a Wraith, unless the target is hit with sustained fire for about seven seconds. Therefore, it is highly advisable to immediately flee from the turret when confronted with a tank.

In contrast to the shielded plasma cannon, the M247's gunner is completely exposed to enemy fire and very vulnerable to snipers and other scoped weapons. Furthermore, the M247 can only traverse 180 degrees, so a wise gunner will recruit an ally to watch their flanks and rear. Also, while this machine gun is capable of firing over long distances, its accuracy is drastically reduced at extreme ranges. Furthermore, it is harder to zero-in at targets beyond ‘standard’ visible range, even with a spotter guiding the gunner's aim. That said, a good two person team can overcome this to a large degree, although the lack of accuracy is still problematic.

Campaign

 * In Outskirts, it can be used to quickly take care of the Hunters. If sustained fire is poured on the doorway, the Hunters will be dead before the dust settles. On the Cairo Station level, players can use the M247 to eliminate the Covenant Boarding party when it docks early in the level. In Metropolis, the M247 appears again towards the end of the level. Here, players can use the turret to quickly dispose of the Elites, Grunts, and Jackals that come pouring out of the Scarab. In Quarantine Zone, however, a barricade of Flood man a triplet of turrets in front of the passageway to the gondola.

Multiplayer

 * The turret usually overlooks a good area and is readily accessible. While the gunner is capable of cutting down waves of infantry, its location and value usually marks it as the immediate and (due to it's static state) "easy" target if the assailant can hit the gunner from behind. Because of this, it is a good idea for the gunner to have a spotter. This is always a good multiplayer tactic, but here it applies especially well as the gunner's rear is completely unprotected, unlike that of it's Covenant counterpart. The mobility of the Shielded Plasma Cannon is 360°, but the M247 only allows a 180° area of fire. Having an ally watching the gunner's back will substantially increase their effectiveness and potential lifespan.
 * On maps with other vehicles, the gunner should be mindful of his limitations. The M247 is effective against infantry and light ground vehicles, not tanks. If an enemy Scorpion Tank or Wraith approaches, the occupant should find cover with utmost haste or be killed.
 * When up against the M247, it is important to focus on the turret's three main weaknesses: its weakness to explosives, lack of cover, and the lack of mobility. Explosives will easily take the emplacement down, a sniper can take advantage of the gunner's lack of cover, and an experienced player will be able to get behind the gunner and take him or her out.

Trivia

 * This weapon shares a very similar name to the real-world Belgian M249 and M240 machine guns, as well as sharing a similar design and combat role.
 * In the Halo 3 Beta, the packaging of the M247 can be found in the map, High Ground.
 * The M247 is replaced by the AIE-486H Heavy Machine Gun in Halo 3. This new variant can be detached from the fixed version, and has a total of 200 rounds of ammunition when detached.
 * Oddly, this weapon is classified as a general purpose machine gun or medium machine gun, even though it uses the 7.62x51mm round. This round (in the time of Halo's universe) is considered an intermediate round used in assault rifles and light machine guns, which would classify the M247 as an LMG. Even more oddly, Halo 3's AIE-486H Heavy Machine Gun is classified as a heavy machine gun even though it too uses the 7.62x51mm. It seems that the UNSC classifies their infantry machine guns based on weight and overall bulk rather than caliber.

Related Links

 * AIE-486H Heavy Machine Gun
 * M41 LAAG