M4/M4A1
The main difference between M4 and M4A1 is that M4 has an "S-1-3" system (safety/single/three-point trigger), while M4A1 It has an "S-1-F" system (safety/single shot/fully automatic) trigger. The early model uses a fixed handle. The M4 with only three-point fire has been replaced by the fully automatic M4A1.
M4 MWS Modular Weapon System
The Modular Weapon System version of the M4, referred to as M4 MWS (also formerly known as M4E2), is equipped with an RIS handguard Colt M925 Carbine and comes with a host of tactical accessories. The Colt Model 925 carbine equipped with an RIS handguard was originally designated as the M4E2 after testing. However, this name was abandoned because of doubts about whether the name should be changed after the existing carbine was installed with this handguard. U.S. Army Field Manual In China, the M-4 series equipped with RAS is called the Modular Weapon System (Modular Weapon System) or M-4 MWS for short.
M4A1 Carbine
The M4A1 carbine (M4A1 carbine) is one of the derivatives of the M4 carbine. It is used for special operations and is now the most common version. Currently, it is mainly equipped with various conventional and special forces of the US military, including Delta Force, US Navy SEALs, US Army Rangers and US Marine Corps.
On April 19, 2007, the U.S. Army signed a M4/M4A1 carbine production contract with a total value of US$50.8 million with M16/M4 gun manufacturer Colt. The contract is expected to be completed in 2008 All implementation will be completed before July 30, 2019.
SOPMOD Block I
Special Operations Peculiar Modification (SOPMOD) Block I, an M4 carbine modification kit developed by USSOCOM for its troops.
Accessories:
KAC RIS (Rail Interface System) rail, KAC front folding mechanical sight and KAC rear folding mechanical sight, M203 grenade that can be quickly installed and removed Transmitter KAC silencer AN/PEQ-2A laser/infrared indicator Trijicon's ACOG scope reflex red dot sight night vision scope M68 CCO red dot sight EOTech reflex sight
SOPMOD Block II
The second generation SOPMOD modification kit (also known as SOPMOD II) is an updated and improved version of Block I. It is now produced by many companies, including KAC (Knight's Armament Company), ARMS (Atlantic Research Marketing Systems), Lewis Machine & Tools, and Daniel Defense produces RIS-II (new generation tactical rail).
M4 carbines produced by different companies have been in service with special forces. Australia's Australian Special Air Service Regiment (SASR) uses Colt's export M4, and the British Special Air Service Regiment (SAS) uses Canadian Dima Branch SFW.
Others
CQBR-is a close combat rifle that replaces the upper receiver and short barrel of the M4 carbine. The barrel is only 10.3 inches (260 mm). CQA Carbine - a flat-top replica version of Norinco. Dimaco SFW and Dimaco C8 - produced by Dimaco in Canada, similar to M4/M4A1 carbines.
With the successful development of the M16A2, the US military has also begun to consider developing a new carbine firing SS109/M885 bullets for special forces. Like the M16A2, this new carbine was designed in 1983 based on the needs of the Marine Corps.
At that time, the small shoulder-fired weapon officially equipped by the Marine Force Recon Company (Force Recon) was only the M3A1 "oil gun" (unofficially used is the XM177E2), and the armored vehicle crew members also used M3A1. The Marine Corps believed that these people should be provided with A carbine. Initially, the M16A2 carbine developed by Colt for the Marine Corps basically just applied the changes on the M16A2 to the Type 653 carbine, that is, it replaced the 1/7 twist 14.5-inch (368mm) heavy barrel and used the M16A2 disappearing gun. Flame weapon, using 3-round burst fire instead of full-automatic shooting, and using the M16A2 mechanical sight. This M16A2 carbine was designed in 1985. It was designated the Colt Model 720 and was called the XM4 in the military's test program. However, Congress rejected the Marine Corps' XM4 procurement budget. As a result, the force reconnaissance company had to use the Navy's HK MP5-N submachine gun to replace the old M3A1 submachine gun, while other US military special forces began to use RO727 and other other equipment in 1988. M16A2 carbine.
The U.S. Army's Test and Evaluation Command (TECOM) resumed development and Phase 2 testing of the XM4 carbine in April 1986. After further testing and improvements, the XM4 was officially finalized and named "The United States Carbine, Caliber 5.56mm NATO, M4" in March 1991. The most obvious distinguishing feature of the M4 from other M16A2 carbines is that its barrel has a constricted shape 25mm in front of the quasi-constellation. This was a change made in later tests to accommodate the M203 grenade launcher. In order to be able to mount the original M203 grenade launcher, the barrel diameter of the M16A2 inside the handguard is the same as that of the M16A1, but the carbine's handguard is shorter and the M16A2-style thick barrel is used outside the handguard, so the Colt Engineers from China processed this necking in the middle of the barrel outside the handguard so that the M203 grenade launcher can be mounted. A fixed stock can also be attached and used, but this is not common in the US military.
The M4 Carbine also changed the telescopic stock that originally had only two fixed positions to four fixed positions, and later to six. In addition, although the rear sight of the M4 is M16A2 style, the rear sight can only be adjusted to a maximum distance of 600 meters, not 800 meters of the M16A2. Since the lower receiver is M16A2, the shooting mode is semi-automatic and three-round burst. Since the M4 and M16A2 are so similar, in fact 80% of their parts are interchangeable, it was originally also called the M16A2 Carbine. The M4 was first equipped with the 82nd Airborne Division and was used to replace the M16A1/A2 rifles, M3A1 submachine guns and some 9mm pistols used by vehicle drivers. It was officially installed in 1994.
The M4 carbine first participated in actual combat in the Gulf War in 1991. Before the war broke out, the U.S. military suddenly discovered that they were short of new rifles. Many troops were still using the M16A1, and the M16A2 only began to be equipped in 1986. Some Many troops have not yet completed the change of equipment. Due to the need to obtain large quantities of M16A2 and M4 as soon as possible, the U.S. Department of Defense approved the increase of M4 suppliers. Bushmaster Firearms of Maine was awarded a procurement contract to supply M4 carbines and supplied 4,000 to the Army. M4, these guns were used by the 82nd Airborne Division during "Desert Shield" and "Desert Storm". It is said that General Schwarzkopf's guards also used the Bushmaster M4. However, the U.S. military had not yet obtained the production rights for the M4 at that time (because the U.S. government had already obtained the production rights for the M16, so the M16A2 production contract could be awarded to FNMI that year). Colt threatened to sue the U.S. government for selling to other companies without permission. After transferring the M4's process documents, Bushmaster only got this one government procurement contract for the M4.
After the M4 was equipped with troops, Colt designed a flat-top receiver that used Picatinny rails instead of fixed handles to facilitate the installation of modular aiming devices.
In August 1994, this improvement was also accepted by the US military, and this flat-top M4 was officially named "The United States Carbine, Caliber 5.56mm NATO, M4A1". The Colt number is 927. Since special forces did not like the burst-fire limiting device of the M4 carbine and used other M16A2 carbines that could fire fully automatically, the M4A1 also used the lower receiver of the M16A1. However, during the test, it was found that the barrel of the M4A1 is prone to overheating. After a shooter fired six magazines in a row in fully automatic mode, the handguard became too hot to touch directly. Although the M4A1 is a carbine rather than a light machine gun, Colt improved the handguard to solve this problem and changed the aluminum heat shield from the original single layer to a double layer, so the guard was thickened accordingly. Wood diameter. This improvement was later applied to the newly produced M4 carbine, so the handguards on the early M4/M4A1 were the same as those on the previous M16 carbine, while the later M4/M4A1 handguards were thicker.
In 1994, the Marine Corps published "Operational Requirements Document 1.14." (Operational Requirements Document 1.14.), which stated that it would take a long-term view of the mission of the force reconnaissance company and use the M4A1 carbine instead of firing The pistol-loaded MP5-N submachine gun will be more effective as a CQB weapon. After some efforts, the Marine Corps finally obtained funds to purchase the M4A1, but mainly to equip special forces. The U.S. Army also officially adopted the M4/M4A1 carbine in August 1994, first equipping special forces and rapid reaction forces.
Most M4 carbines with a limit of 3 bursts are equipped with crew members, crew members, clerks or officers. For example, M1 tank crew members have used 4 M3A1 submachine guns as self-defense weapons for many years, but now they use Two M4 carbines and two M9 pistols. Since the flat-top receiver is convenient for installing sights, except for the early orders with A2 handles, all M4s purchased by the US military now use flat-top receivers. The sights are mainly Trijicon's TA11 and TA31 ACOG and Aimpoint M68 CCO. The current government standard M4 series are Colt Model 920 (flat-top M4, speed machine "S-1-3") and Colt Model 921 (M4A1, speed machine "S-1-F").
The Colt Model 925 carbine equipped with the KAC M4 RAS handguard was designated as the M4E2 after testing, but this name seems to be due to whether the name should be changed after installing this handguard on the existing carbine. Confused and given up. The U.S. Army Field Manual refers to the M4 series equipped with RAS as the Modular Weapon System (Modular Weapon System) or M4 MWS for short.
Although the M4A1 was developed for Special Forces, the Army announced in 1998 that it planned to replace the M16A2 with the M4A1 with a RAS handguard as the standard rifle in regular forces, while the original M16A2 was transferred to reserve forces and Coast Guard (Note: Other information indicates that the replacement plan will be carried out from November 1997, and it is planned to be completed by the end of 1999). Why would the Army want to replace the standard assault rifle with a carbine? The Army's explanation is that the M4A1 is lighter than the M16A2 and is effective enough to deal with targets within a 200-meter range; another explanation is that when the "Land Warrior" system is equipped with troops, the M4A1 can reduce the total weight of the system. But there is actually another rumor that some senior generals within the Army are still very upset about FNMI beating Colt to obtain the M16A2 supply contract in 1988 due to its price advantage, because FNMI is a foreign-backed company. If the Army decided to adopt a different model of rifle, it would have reason not to continue with the purchase contract with FNMI.
The procurement of the M4A1 caused a lot of controversy, and when Colt received the Army's production contract, FNMI immediately proposed that they could also produce the M4A1 for the Army. The Army rejected the offer, and FNMI filed suit in U.S. federal court, arguing that it was unfair for the U.S. government to appoint the sole contractor.
A federal court dismissed FNMI's complaint following Colt's campaign, explaining that the M4 series' technology was proprietary to Colt and that, in accordance with a December 1997 agreement between Colt and the Army, the Army's 2011 No production rights or process documents of the M4 series may be granted to other manufacturers before.
The peak of the Army's procurement of M4A1 was around 2000. In 2001, the U.S. Army finally decided to equip regular troops with the M16A4 with RAS handguards. This seemed to be evidence of the rumor. The Army still purchased the M4A1 from Colt. Purchase M16A4.
Since the shorter barrel results in lower muzzle velocity and greater muzzle noise, and the handguard is more likely to heat up than the long rifle, the Marine Corps has repeatedly debated whether to adopt the M4A1 or retain the M16A2. Debate eventually led to the announcement in September 2002 that the M16A2 would be replaced by the M16A4 with a RAS handguard, but produced by FN. Many dismounted infantrymen on the Afghan battlefield complained about the shortcomings of the M4A1's insufficient range, which prompted the Marine Corps' decision. However, in the urban combat of the 2003 invasion of Iraq, those mechanized infantrymen who still used the M16A2 felt that they There is a greater need for short and powerful light weapons like the M4. This is because the combat distance in the city is much closer than in the mountains of Afghanistan, and even when fighting in the suburbs, these members of the mechanized force do not need to use the light weapons in their hands to deal with targets 300 meters away. Most of the troops who complain about the insufficient range of the M4A1 are light infantry who lack heavy weapons support.
Although the effective range of the M4 series is not as far as the long-barreled M16 series, many military analysts believe that infantry light weapons do not need to shoot at 300-meter targets in most cases, as long as they are effective within 150m. The M4 series is favored by counter-terrorism forces and special forces due to its compact shape and powerful firepower (only the fully automatic M4A1) is suitable for CQB. These advantages are also suitable for urban combat, so in infantry squads of conventional forces, the M16A4 is the Mainly paired with a small amount of M4A1 has become a popular model. Among quick reaction forces such as special forces and airborne troops, M4A1 is the main battle weapon. The United States Special Operations Command (USSOCOM) adopts M4A1 as the standard rifle.
In recent years, Colt has produced M4A1 or modification kits with thickened barrel parts inside the handguard. Although the overall thickening of the barrel will slightly increase the weight, it is more reliable when firing fully automatically. Heat resistance is also more accurate. These heavy-barreled weapons also come with a new, slightly heavier buffer called the H2. The standard H shock absorber has a sliding weight consisting of one tungsten and two steel pieces, while the new H2 shock absorber has two tungsten and one steel pieces. These weapons are currently known as the Colt 921HB (Heavy Barrel), but the HB improvements adopted by the military were not renamed, so the government M4A1 includes the 921 and 921HB.
In addition to being equipped in the US military, the M4 series is also exported to other countries, and Colt also provides four models of M4/M4A1, RO777, 779, 977 and 979, to law enforcement agencies.
In addition to RO977, Colt Company also provides law enforcement agencies with a long barrel M4A1 with a barrel lengthened to 16.1 inches, called "Law Enforcement Carbine", product number LE6920 . The gun comes with two 20-round magazines. Of course, users can also buy magazines with other capacities. The LE6920 has two types of receivers: a fixed handle receiver and a flat-top receiver. The lower receiver has two firing modes: three-round burst fire and continuous fire.
Currently, the Colt M4 is restricted to sales to the military and law enforcement agencies. Only under special conditions can civilians be allowed to own the government M4/M4A1. According to the definition of BATF, a 14.5-inch barrel is classified as a "short barrel rifle" (BATF's definition of "short barrel rifle" is "a rifle with one or more barrels shorter than 16 inches in length, and the total length is not should be shorter than 26 inches in total length), fall into the Class III weapons category, while weapons capable of burst fire (including burst mode) are classified into the machine gun category.
To purchase level three weapons or machine gun weapons, you must apply for and pay stamp duty to BATF, and civilian machine gun weapons can only be owned and sold before 1986, because federal law prohibits production in the United States from May 19, 1986. Businessmen and dealers sell machine gun weapons to civilians (note: civilian ownership of imported machine guns is limited to guns imported before 1968). The only exception is Special Occupational Taxpayers (SOT), who are dealers and manufacturers who produce, import and export machine guns. There are also private security or military companies such as security contractors. Only the earliest Colt M4 prototypes produced before May 19, 1986 can be legally owned by a non-SOT civilian.
It is said that Colt’s exclusive contract to produce the M4 series for the US government was signed until 2009, but not all M4s exported were Colt products, according to an administrator on SecurityArms According to the information provided to me by PIERANGELO TENDAS (an Italian), the M4A1 used by Italian special forces is a Bushmaster product. In addition, in the private sector, there are many manufacturers that produce weapons that are very similar in appearance to the military M4, called M4 style rifles (M4 style rifles). Usually these M4-looking weapons have 16-inch barrels (avoiding the category of Level 3 weapons) and are semi-automatic only. They all imitate the M4 with a constriction in the middle of the barrel, although many of the fake M4s who buy these Most people will not buy an M203 grenade launcher (it is a level three weapon and expensive), but they buy this short AR-15 rifle with a necking on the barrel just because of the name "M4". There are many manufacturers producing M4 style for civilian use, Bushmaster, Olympic, etc. are also more famous.
Colt has been dissatisfied with the situation as it wants to maintain its exclusive rights to the M4 name and design; other manufacturers have long claimed that Colt is over exaggerating their Right - they say "M4" is now a collective term for the short M16/AR-15. In April 2004, Colt filed a lawsuit against HK and Bushmaster for trademark infringement, trade infringement and trademark dilution, alleging that they intentionally and incorrectly used trade names, infringed Colt's patents, and used unfair methods. competition and deceptive trade practices. HK's appeal was rejected by the court, so HK had to change the shape design of their short-stroke piston HKM4 and renamed it HK416. However, on December 8, 2005, a federal district court judge in Maine ruled in favor of Bushmaster (similar to FN's situation, it seems to be caused by local protectionism). Since Colt actually lost the "M4" trademark in its lawsuit against Bushmaster, the court simply revoked Colt's M4 trademark patent rights.