MA5B assault rifle

Advantages
When fired in short bursts to increase accuracy, the assault rifle is effective at killing unshielded opponents and weaker enemies (especially when they are in larger groups) at short-to-medium range. This includes Covenant Grunts, Jackals (only when shield is down or when shooting their flank), and all variety of Flood. The assault rifle is also effective for destroying Banshees, Ghosts, and other Covenant vehicles (Campaign only). It is highly effective against Elite Rangers who attack with active camouflage. Aside from being able to quickly cut down these unshielded elites, the high rate of fire disrupts their camouflage and makes it very easy to center on them for a quick finish.

As an added bonus, the gun gives the player an at-a-glance ammo count on its digital readout, as well as an arrow pointing toward the gas giant Threshold (which acts as a compass).

The 60-Round clip size is also a bonus as it aids to mow down any unshielded Elite, any Grunts, Jackals or Flood which get in its way.

Disadvantages
The assault rifle performs poorly against shields and, in comparison with the pistol, is largely inaccurate. In addition, the assault rifle's high rate of fire necessitates frequent reloading. Later in the game, it is almost completely overshadowed by the shotgun; though in multiplayer this is less apparent, as the amount of ammo available for the shotgun is much less than for the AR.

Advanced Tactics
The Assault Rifle is weakened for multiplayer. however there a couple things you can do to make the most of this weapon, when no other close range weapon is around.
 * The AR's accuracy degrades after EXACTLY 1.5 seconds of sustained fire. In order to use this weapon to it's fullest, you must learn the most efficient bursts to use at different ranges. Failure to do so results in missed shots, wasted ammo, and lives lost.
 * The AR's melee attack is extremely quick, the fastest other than the Plasma Pistol. When up against anything other than a shotgun or a Plasma Rifle, use it.
 * When used with effective grenades, the AR can hold its own. Backpedal and use any 'nade you have handy, and let the gun take care of your enemy after his shields are down.
 * In Halo PC, you have to lead your target, just like all of the other weapons. In the Xbox, this isn't a problem due to autoaim.
 * Bunny Hop with the AR. It's your best defense against anything but a sniper. But watch out for ledges!
 * When up against a Sniper (or in some cases, a pistol-wielder) use 'nades and strafe in a circle. Only open up when you're within range. There's nothing worse then an empty mag when you're finally able to take the kill.
 * Even at long ranges, you can still use the AR to protect yourself from snipers. Remember: it only takes one shot to knock them out of their scope! Use this when you accidentally expose yourself, or when you just need to get to a better position.
 * If your enemy is using a Banshee in multiplayer, this weapon is choice. Just point it in a generally upward direction and they will be dead in seconds.

Multiplayer Role
Since players in Halo multiplayer normally spawn with shields, the assault rifle's effectiveness is limited. It is often used only because more specialized weapons are unavailable. However, when combined with the plasma pistol (which can destroy shields quickly), the assault rifle can be a powerful short and medium range option. It takes about 15 accurate rounds to kill a spartan normally.

Appearences
The Assault Rifle was introduced as the default weapon in Halo 1. Unfortunately Bungie did not like how the rifle behaved, so it did not make it into Halo 2 and was "replaced" with two weapons: the Battle Rifle and the SMG. This weapon will return in Halo 3 as the MA5C Assault Rifle.

Trivia

 * It is interesting to note that the sound effects for the assault rifle are also the same sounds as the MG42 Machine Guns in the HBO TV series Band of Brothers.
 * One inspiration for the MA5B Assault Rifle was the "MA–75B Battle Rifle (with integral 40mm Grenade Launcher)" from the Marathon series. In fact, before Bungie reengineered the game for the Xbox, it was fitted with a grenade launcher. [[Image:F2000.jpg|thumb|The modern day [[Wikipedia:FN F2000|FN2000]]]]
 * Another inspiration is the MA5B Assault Rifle design seems to be taken from the M-590 7.62mm assault rifle of the USMC from 1995-1996 TV series Space:Above and Beyond.
 * Robert McLees at Bungie has gone on record comparing the basic design of the MA5B to that of the Fabrique-Nationale, FN2000