M16A4

The M16A4 is an assault rifle capable of firing in semiautomatic and three round burst modes, and is an updated version of the M16A2 rifle. The M16A4 rifle differs from the standard fixed sight M16A2 in that it has a MIL-STD-1913 Picatinny rail under the removable carrying handle which allows different types of optics to be easily mounted on the top of the receiver. There are also Picatinny rails mounted on the handguard to allow lasers, flashlights, foregrips, and grenade launchers. It is the current standard issue rifle of the US Marine Corps and some Army units. The weapon is light and accurate, but requires frequent cleaning, partially because it is susceptible to dirt, but also because its internal mechanism lacks a piston; the gases strike directly onto the bolt of the rifle, which is lighter but results in less reliability as carbon is blown into the chamber. Fortunately, the game is devoid of such problems.

Singleplayer
It is exclusively available in War Pig, dropped a few times (rarely with M203) by some incapacitated Marines at a certain juncture, and in either case with iron sights. In single player the M16A4 incorrectly fires in fully automatic rather than the real M16A4's three round burst.

Multiplayer
This is one of the initial weapons available at level 1. It's highly powerful and quite accurate, which is only further enhanced by its three round burst firing mode. This rifle can be fitted with a suppressor, Red Dot Sight, ACOG Scope, and Grenade Launcher. The weapon is designed primarily for medium to long range engagements, and can usually if not always drop enemies in a single three round burst if the Stopping Power perk is equipped. It is often deemed "cheap" by other online players because of this.