M4 Carbine


 * For the related rifle, see M4A1

The M4 Carbine is a three-round burst rifle found in Call of Duty: Modern Warfare: Mobilized and in Call of Duty: Modern Warfare 3: Defiance as a fully automatic rifle.

Call of Duty: Modern Warfare: Mobilized
It is almost a copy of the M16A4 found in Call of Duty 4: Modern Warfare. Notable differences are that the 3-round burst has a slower rate of fire, more compact iron sights, and a smaller delay between the bursts.

Singleplayer
In single player, the M4 Carbine is exclusive to the level "Closing In", though it can be seen in use by allies in all the missions of the American campaign. It produces the same sound as the M4A1, but it has a lower damage per bullet, still killing with one burst. Due to its 3-round burst and only extra 120 rounds that come with it, the M4 is the least ammunition efficient weapon.

Multiplayer
In multiplayer, the M4 Carbine is available by default, along with the MP5 and MP7. It is probably the least common weapon used in multiplayer, due to its lack of power, as it takes two bursts to kill, and low ammunition efficiency. Those who do use it usually discard it when the M4A1 is unlocked, since it has much higher power and the same rate of fire as the M4 Carbine, only without the delay between bursts.

Call of Duty: Modern Warfare 3: Defiance
The M4 returns in Call of Duty: Modern Warfare 3: Defiance, this time ,as a fully automatic rifle.

Single Player
In single player, on various missions the player starts with the M4 as a equipped weapon weapon, and later in the game the M4 can be picked up with various attachments. Instead of its Mobilized counter part, the M4 is now a full automatic.

Multiplayer
One of the four weapons initially available to the player in Multiplayer, the M4 takes nearly a quarter of its clip to down an opponent. Players will find themselves using this most of the time when first playing Multiplayer, and will also find themselves discarding it once they've unlocked its scoped counter part and/or assault rifle unlockables.