The M16 fires in three-round bursts in multiplayer, like theM16A4 from Call of Duty 4: Modern Warfare and Call of Duty: Modern Warfare 2. It is part of the default "Assault" class. After having unlocked Create-A-Class, it does not need to be purchased with CODPoints.

The weapon has high damage with moderate recoil, offset by mechanical burst-fire, meaning it is most effective at medium-long range, especially since it maintains its damage up to longer ranges than all other assault rifles, meaning the M16 has the best range of all Assault Rifles. However, the forced delay between each burst makes it less effective than automatic weapons at close range. All three rounds must hit at close to medium range for a kill, while four rounds are needed for kills at long-range, meaning that usually two bursts are needed at long range. However, if all three rounds hit, and one of them is a headshot, then it is capable of a one-burst kill at long range. The M16 is moderately popular online. Due to its burst fire, it is advised to use at medium range or longer, as at close range it will lose to any shotgun, sub-machine gun, or automatic assault rifle. It's advised to have dual wield pistols as secondaries to enhance the player's close-quarters abilities.

The M16 is, for the most part, the same as its Modern Warfare incarnations, although its default range is longer. It is, however, slightly less effective due to the lack of Stopping Power, as more than one burst on target is needed for a long-range kill, and with the firecap being lower than the G11 makes it less popular.

The Infrared Scope and ACOG Scope actually lessen recoil, which is different from the rest of the weapons when equipped with those two attachments. The M16 with any attachment besides the grenade launcher has a solid color on the heat shield.

The M16 and G11 compare to each other in that both are fired in three-round bursts. The M16 is unlocked much earlier, has superior damage (40-30 to 35-25), has more available attachments (compared to scopes), and boosts the best range of all the Assault Rifles. The G11's advantages include a higher firecap (meaning that the AR is more able to recover), a larger magazine (48 rounds puts it on top of all the other AR's), and having the hipfire of SMGs. Because of this, many people deem the G11 superior to the M16 and is more common than it. However, the M16 is capable of being a competitive Assault Rifle nonetheless.