M4A1 Carbine

The M4A1 Carbine is a short-barreled, telescoping-stocked variant of the M16A2, derived from the AR-15. The M4A1 Carbine fires the same 5.56x45mm round as the M16. The M4 Carbine was designed to be a defensive weapon for personnel whose role may require a powerful defensive weapon when a full-sized rifle may be impractical. The M4 is also used by various special forces for its compact nature and full-power rifle cartridge, making it ideal for close quarters combat. To this end, a variety of modifications for the M4A1 Carbine, known as the Special Operations Peculiar MODification (SOPMOD) kit, are issued to US military special operations forces, which include the Knight's Armament Company vertical foregrip, M203, Knight's Armament Company QDSS-NT4 Suppressor, AN/PEQ-2A, ACOG Scope, and other accessories. The US Army's units vary between keeping the M16, issuing the M16 to some soldiers and the M4 to others, and replacing the M16 entirely, and the US Marine Corps still largely uses the M16. The M4 is also used by many other countries including Israel, Japan, Australia, Greece and Mexico. All though the M-16 is still the main stay of the United States Military the M4 is becoming more common in special forces units.

Call of Duty 4
In singleplayer, the M4A1 (with a Tasco Red Dot Sight, AN/PEQ-2A, and foregrip) is a frequently dropped weapon among the Marines, and an infrequently dropped weapon among the SAS troops. It is the starting weapon in Charlie Don't Surf and Game Over, and one of the optional weapons at the beginning of Hunted. The "M4A1 Grenadier", which uses an EOTech Holographic Weapon Sight, AN/PEQ-2A, and M203, is the starting weapon in The Bog, War Pig and Shock and Awe. The "M4A1 SOPMOD" uses the red dot sight, M203 grenade launcher, AN/PEQ-2A infrared laser, and silencer, and is the starting weapon in the majority of MacTavish's missions. Captain Price uses it in all missions. Surprisingly, in the SAS missions, the M4A1 SOPMOD seems to have all attachments available, a red dot sight, silencer, grip (though the M4A1 Carbine has a grip, this does not serve to decrease recoil and does not count as an attachment. Note that the grip does not show from the third-person perspective in-game, as when dropped or held by another character, in both single-player and multiplayer), and an M203.

In multiplayer, the M4A1 Carbine has an attached foregrip. It can be modified with the Red Dot Sight, ACOG Scope, M203, or silencer. The M4A1 Carbine is fully automatic with moderate damage and very low recoil, but it has very high idle sway (4 degrees) and idles very fast, making it more difficult to aim with at long range. This was done for balancing purposes because the M4A1 was incredibly overpowered in the beta, in which it had no idle sway. The M4A1 also shares ammo with the M16A4 and the G36C. The M4A1 Carbine is one of the most commonly used weapons in online multiplayer on all platforms.

Weapon Performance
As stated above, the M4A1 is not particularly effective at long range due to its sway on consoles. In the PC version, however, idle sway is easily compensated for with the mouse, making it very effective at all ranges. The M4 is ideal in close quarters combat due to its high rate of fire. Steady Aim makes the M4 a fairly effective hip-fire weapon. Double Tap can be quite effective due to low recoil and low damage, but ammo use increases dramatically.

The weapon's low damage output can be compensated by its high rate of fire, and the very low recoil allows for accurate full automatic fire at short and medium ranges. Because of this, Bandolier can be useful.

Call of Duty: Modern Warfare 2
The M4A1 returns in Modern Warfare 2, and has retained most qualities and appearances of the Call of Duty 4 version. The M4 in this game is actually very similar to the Bushmaster Modular M4 Carbine, except that the game version has a shorter barrel, indicating that it is a version built for close combat. The AR-15 carry handle which was present in the first game has been replaced with foldable PRI front and ARMS #40L rear sights and the Knight's Armament Rail Interface System (RIS) has been replaced with an ARMS Selective Integrated Rail (SIR) System. It now sports tan camouflage, as opposed to the previous gunmetal color. It noticeably has a band around the magazine, and at times it can be misidentified as a SCAR-H rifle because of it's sights and the overall color of the weapon. Also, the forward grip has been removed from the underside tactical rail system. The M4 comes in many variants in the singleplayer campaign, such as the M4 SOPMOD(Special Operations Modification Kit), (RDS, M203, and Silencer), M4 Grenadier w/ Holographic, M4 Carbine, etc. Online it is commonly used with the Red Dot sight. Its the most common weapon used in campaign and multiplayer, with FMJs and Holographic Sights, ACOG Scope, and/or Grenade Launcher makes it a powerhouse in such maps as Estate, or Highrise.

Weapon Attachments
 * Grenade Launcher (Marksman I)
 * Shotgun (20 kills with the Grenade Launcher)
 * Red Dot Sight (Marksman II)
 * Holographic Sight (60 kills while aiming down the Red Dot Sight)
 * Silencer (Marksman III)
 * Heartbeat Sensor (15 kills with the silencer attached)
 * ACOG Scope (Marksman IV)
 * Thermal Scope (20 kills while aiming down ACOG)
 * FMJ (Full Metal Jacket) (Marksman V)
 * Extended Mags (40 kills with Bullet Penetration while using FMJ)

Call of Duty: Modern Warfare: Mobilized
The M4A1 in Call of Duty: Modern warfare: Mobilized is very similar in appearance and damage compared to the one in Call of Duty 4. It is an assault rifle that you start out with in the first few missions of the American campaign. It has a higher rate of fire than the console version.

Trivia

 * It is inaccurate to call the M4 in multiplayer the M4 Carbine, as the original M4 carbine featured a 3 round burst option, much like the M16A2. The M4A1 is the fully automatic version.
 * In Modern Warfare 2, when using the FMJ attachment on the M4, there will be no foregrip on the gun (as seen when reloading) but the player will still hold the gun as if there is.
 * On the lower receiver of the M4A1, it says " BLUE4 ". It also says, "Property of U.S. Government, Caliber 5.55mm, M4A1 Carbine" over the magazine housing. However, the M4A1 Carbine fires a 5.56mm, not a 5.55mm, and it is also used by the SAS in game. It saying "5.55" is most likely a typo or part of a way to avoid copyright.


 * The SAS are not known to use the M4A1, but rather the cosmetically similar Diemaco C8SFW, which carries the Land Force designation L119A1. However, they have such a large array of weapons at their disposal that it is possible.


 * If you attach an M203, the amount of recoil felt will be slightly increased, but not by much. This also applies with the M16A4. The effect should be opposite, however, because the M203 adds weight to the weapon, and adding weight has the effect of reducing recoil. It could be argued however, that the removal of the vertical grip on the M4A1 could be why the recoil is increased.


 * If you set the sensitivity on console versions to 10 (max) then spin in circles clockwise (to the right) the right side of the gun can be slightly visible, showing a much less detailed texture. This was done because that side of the gun is not normally visible and not detailing it saves memory.


 * The M4A1 and the M16A4's front sights disappear when another optic is attached.


 * There is a special version of the M4A1 called the M4A1 Suppressed, NPCs use it and it can only be acquired by using cheats.


 * The M4A1 Carbine is the very first weapon you are able to use in Call of Duty: Modern Warfare 2.
 * The M4A1 iron sights in Call of Duty: Modern Warfare 2 are somewhat similar aesthetically to the M249 SAW's sights from Call of Duty 4.
 * In Modern Warfare 2, The M4A1 Carbine's pickup icon has the vertical grip attached, although it is removed in the Create-A-Class picture.
 * In Modern Warfare 2, the gun sounds like the Call of Duty 4 M4 in the singleplayer campaign, but in multiplayer, the gun sounds quite different, with a lot more punch in the sound.
 * The M4A1 in Modern Warfare 2 resembles a HK416 more than a M4A1.
 * In the beginning of the Modern Warfare 2 level "Only easy day was Yesterday" The M4 is titled as M4 SOPMOD but later in the level it changes to just M4A1.