UNSC Weaponry

The UNSC have a wide variety of weapons in their arsenal which all have their own strengths, weaknesses and unique capabilities. Though they are not highly effective against shielded foes, they are deadly against non-shielded foes. They are effective on easy and normal to gun down all Covenant. The automatic fire of some of them can take down an Elite extremely quickly on both Halo: Combat Evolved and Halo 2. They are also far more effective than most Covenant weapons against the Flood, with some exceptions.
 * See also: Development of UNSC Weapons

M6D Magnum Sidearm
A small handgun with surprising effectiveness. Its X2 scope allows for easy headshots, and it serves well against Hunters. Performs well against Flood Combat Forms and Carrier Forms, often requiring only 3-5 rounds and ~2 rounds, respectively, to kill.

MA5B ICWS Assault Rifle
The most commonly-used human weapon in Halo: Combat Evolved. It can take down an Elite fairly easily on lower difficulty levels, but may require more than one clip for high ranking Elites on Heroic and Legendary. Second-most effective weapon in close combat with the Flood.

M90 Shotgun
Can kill an Elite in one shot on Easy and Normal, and it's very effective against them on Heroic and Legendary. Can wipe out a pack of Grunts with 1-3 shots. The most effective close range weapon against the Flood.

SRS99C-S2 AM Sniper Rifle
Very effective from long distance. Has a X2/X8 scope with a night-vision ability. Usually a one-hit-kill with headshots on all difficulties. Fairly poor from close range and does no damage to the Flood whatsoever. As of Halo 2, the zoom is X5/X10, and the night-vision capability has been removed.

M19 SSM Rocket Launcher
Extremely effective against large groups of enemies and vehicles. Has a X2 scope. The Halo 2 variant had homing capabilities against vehicles. Also very effective against the Flood. Useless from close range as it will kill the player as well. On Legendary it takes more than one rocket to kill a major Elite.

M9 HE-DP Grenade
Better known as the Frag Grenade, can deliver large amounts of damage over a reasonbly large area. The main advantage over any of the Covenant grenade types is the frag's ability to be bounced off walls, and therefore round corners.

M7057 Defoliant Projector Flamethrower
Available in Halo PC mulitplayer and Halo 3 as a Support Weapon. Deals a fair amount of damage to all enemies, and is especially effective against the Flood in Halo 3.

BR55 Battle Rifle
A mid-range burst rifle, capable of getting headshots. Useful in certain situations, added in Halo 2 to replace the MA5B as the primary combat rifle. Fairly effective against the Flood if you aim for their chest. Underwent a major cosmetic overhaul for Halo 3.

M6C Magnum Sidearm
A stripped down version of the M6D pistol used in Halo: Combat Evolved. Not as effective without a scope but still good with headshots. Fairly ineffective against the Flood without getting dangerously close.

M7 SMG
Very high rate of fire and good when dual wielding. It has a high recoil, meaning the wielder must actively hold it down for increased accuracy.

M7S Submachine Gun
A variant of the above SMG, featuring a supressor. Found in the map "Example" featured in the Halo 2 Vista map editor. Not available in campaign mode.

M6G Magnum Sidearm
This handgun is almost a hybrid of the two previous handguns. It possesses much of the M6D's looks, and much of the M6C's functionality. A smaller clip and slightly more power are the only non-aesthetic differences to the Halo 2 M6C.

Spartan Laser
This shoulder-wielded focus-energy beam weapon is more than capable of destroying most vehicles in one hit. It deals a fair amount of splash damage, rendering it viable as an anti-personnel weapon. There areonly two disadvantages; Each shot requires one-fifth of the non-replaceable battery, and the weapon takes 3 full seconds to charge up each shot.

Missile Pod
Making up for the rocket launcher's lost ability to lock-on in Halo 3, the missile pod will home in on vehicular targets (much like the Hornet's rockets). This is a turret weapon, but can be removed and wielded as a support weapon. After being detached, it has 8 non-reloadable missiles.

MA5C ICWS Assault Rifle
A slightly stripped-down version of the MA5B from Halo: Combat Evolved, it features a 32-round clip and a slightly slower rate of fire. It is, however, slightly more powerful. It is almost identical in looks to the MA5B.

M90A CAWS Shotgun
Though still as effective against the Flood, the Halo 3 shotgun has a smaller magazine than it's earlier counterparts, and is less powerful.

Non In-Game Weapons
Below is a list of other UNSC weapons of the Halo Universe that may not appear in any of the Halo games.

HMG-38 Rifle
The HMG-38 was used by UNSC Marines until they became obsolete in 2525.

M6A Handgun
The M6A is a variant of the M6 series sidearm mentioned in a Bungie update on the M6G.

M6B Handgun
The M6B is a variant of the M6 series sidearm mentioned in a Bungie update on the M6G.

M6J Carbine
The M6J is an UNSC Army variant of the M6 Pistol series.

M90A Law Enforcement
The M90A LA is a variant of the DTM Series.

M99 Stanchion Gauss-rifle
The UNSC Army's resident Long-range, anti-material weapon.

MA2B Assault Rifle
The MA2B is a cut down version of the standard MA5B.

MA3 Assault Rifle
The MA3 is an older variant of the MA5B Assault Rifle.

MA5K Carbine
The MA5K is a cut-down variant of the standard MA5B Assault Rifle.