 | M4 Carbine: Encyclopedia II - M4 Carbine - History and variants
M4 Carbine - History and variants
The M4A1 carbine, an improvement upon the M4 carbine intended for Special Operations use, features a fully-automatic fire mode, a flat-top NATO M1913-specification rail on top of the receiver (for attachment of optical sights and other aiming devices — Trijicon TA11 and TA31 ACOGs and Aimpoint M68 CCOs being the favorite choices), and a detachable rail-mounted carrying handle. The M4A1 can be found in use by many U.S. military units, including the U.S. Army Rangers, Delta Force, U.S. Navy SEALs, and the United States Marine Corps Force Reconnaissance companies.
As of 2001, both the M4 and M4A1 classifications represent carbines with detachable carry handles allowing for optics to be more easily mounted. The current government standards are the Colt Model 920 (M4) and 921 (M4A1). The major difference between these models is that the M4 has the "S-1-3" (safe/semi-automatic/3-round burst) fire modes, while the M4A1 has a "S-1-F" (safe/semi-automatic/fully-automatic) fire modes. Also, in the last few years M4A1 carbines have been being refit or received straight from factory with barrels with a thicker profile under the handguard, for a variety of reasons such as heat dissipation during full-auto and accuracy as a product of barrel weight. These heavier barrel weapons are also fitted with a heavier buffer. These weapons, Colt Model 921HB (for Heavy Barrel), have also been designated M4A1, and as far as the government is concerned there the M4A1 represents both the 921 and 921HB.
Variants of the carbine built by different manufacturers are also in service with many other foreign special forces units, Australia's Special Air Service Regiment (SASR). While the Australian SASR uses weapons of essentially the same pattern built by Colt for export (Colt uses different models to separate weapons for the U.S. military and those for commercial/export purposes), the British SAS uses a variant on the basic theme, the SFW built by Diemaco of Canada. Ironically, this distinction is now essentially redundant with the purchase of Diemaco by Colt.
The M4A1 Carbine is specially favored by counter-terrorist and special forces units because of its compactness and firepower that the rifle offers for close quarters combat. It is very useful in urban warfare. Although the M4 does not have as far an effective range as the longer M16, many military analysts consider engagement with a non-specialized small arm above a range of 300 m to be unnecessary. It is extremely effective at 150 m or less. It appears as a stereotypical weapon in many modern video games, such as Counter-Strike.
Colt Model 925 carbines were tested fitted with the KAC M4 RAS under the designation M4E2, but this designation appears to have been scrapped in favor of mounting this system to existing carbines without changing the designation. The U.S. Army Field Manual specifies for the Army that adding the Rail Accessory System (RAS) turns the weapon into the M4 MWS or Modular Weapon System.
The Special Operations Peculiar Modification (SOPMOD) I M4A1 Kit was developed by USSOCOM for use with units under its jurisdiction. The kit features an M4A1 carbine, a Rail Interface System (RIS) handguard system developed by Knight's Armament Company (KAC), a shortened quick-detachable M203 grenade launcher and leaf sight, a KAC sound suppressor, KAC back-up rear sight, an Insight Technologies AN/PEQ-2A visible laser/infrared designator, along with Trijicon Advanced Combat Optical Gunsight Reflex optics and a night vision sight. This kit was designed to be configurable (modular) for various missions and the kit is in service right now with Special Operations units (though many soldiers have changed the Trijicon reflex sight for M68 Aimpoint red dot sights and EOTech holographic sights).
AR-10, AR-15
M16, M16A1, M16A2, M16A3, M16A4
M4, M4A1 Carbine
Diemaco C7, C8
CAR-15
Colt Commando
Colt M231 FPW
SDM-R, SAM-R
Mark 11 'SWS'
Mark 12 'SPR'
SEAL Recon Rifle
Mark 18 'CQBR'
Ares Shrike
La France M16K
A 2nd generation SOPMOD (now known as SOPMOD II) is currently under development, with many different manufacturers competing for a contract. Notable manufacturers include Knight's Armament Company and their URX II, ARMS and their Selective Integrated Rail (SIR) system, along with Lewis Machine & Tool's Monolithic Rail Platform (MRP).
As mentioned, the M4 replaced the M3A1 submachine guns that remained in service, mainly with tank crews. They had previously had M3s, but this was changed to two M4s and two M9 pistols ('Personal Defense Weapons'). This was as much to increase capability as it was change over from .45 cal, as M3A1s could be configured to fire 9 mm ammunition.
Other related archives.45 cal, 1960s, 2001, 5.56 mm, 5.56 mm NATO, 9 mm, ACOGs, AN/PEQ-2, AN/PEQ-2A, AR-10, AR-15, Advanced Combat Optical Gunsight, Afghanistan, Aimpoint, Ares Shrike, Armalite, Australia, Bureau of Alcohol, Tobacco, Firearms, and Explosives, Bushmaster Firearms, CAR-15, Colt Commando, Colt Firearms, Colt M231 FPW, Counter-Strike, Delta Force, Diemaco, Diemaco C7, C8, EOTech, Force Reconnaissance, H&K 416, KAC, Knight's Armament Company, La France M16K, List of crew served weapons of the US Armed Forces, List of individual weapons of the U.S. Armed Forces, M1 Carbine, M16, M16, M16A1, M16A2, M16A3, M16A4, M16A2, M16A4, M1913-specification rail, M203, M3A1, M68 Aimpoint, M68 CCOs, M9, M9 Bayonet, Maine, Mark 11 'SWS', Mark 12 'SPR', Mark 18 'CQBR', Marksmanship, NATO, Natick Soldier Center, Operation Anaconda, Personal Defense Weapons, SAM-R, SAS, SASR, SDM-R, SEAL Recon Rifle, SFW, SOPMOD, Special Air Service Regiment, Special Operations, Trijicon, U.S. Air Force, U.S. Army Rangers, U.S. Navy SEALs, U.S. Special Forces, USSOCOM, United States Marine Corps, United States Special Operations Command, United States government, XM177, XM26 LSS, XM29 OICW, XM8 carbine, ammunition, assault rifle, barrel, bipods, bullet, carbine, carbines, civilian, close quarters battle, counter-terrorist, firearms, full auto, gas-operated, grenade launcher, holographic, infantry, infrared, laser, leaf sight, machine gun, magazine, night vision, optical sights, optics, pistols, red dot sights, reflex sight, selective fire, semi-automatic, shotgun, sound suppressor, special forces, stock, submachine guns, summary judgment, tank, trademark, urban warfare
 Adapted from the Wikipedia article "History and variants", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki |
