M16 rifle

The M16 (officially Rifle, Caliber 5.56 mm, M16) is the United States Armed Forces designation for a variation of the AR-15 rifle.. The Colt company purchased the rights to the AR-15 from ArmaLite and currently only uses that designation for semi-automatic versions of the rifle. The M16 fires the 5.56×45 NATO cartridge. It entered service with the United States Army and was first deployed for Vietnam War operations in South Vietnam in 1963, becoming the standard rifle of the FF. AA. Americans in 1969, replacing the M14 rifle in that role. The United States Army maintained the M14 in service in the continental United States, Europe, and South Korea until 1970. The M16 has been widely adopted by militaries around the world. Total production of M16 rifles since the beginning of its design is approximately eight million, being the most produced weapon of its caliber. The M16 came to be replaced in the United States Army by the M4 carbine, which is a short version derived from the M16A2.

History

Background

Traditionally, the US military favored long-range precision shooting; the soldier was taught to shoot from a distance and hit the first shot. Therefore, powerful ammunition and rifles that fired it with great precision were sought, such as the M1 Garand.

After the Korean War ended, the US Army saw the uselessness of powerful cartridges and decided to seriously look for an assault rifle that could replace the M1 Garand. In parallel, following the path indicated by Germany with its Stg 44 rifles, a less powerful but effective cartridge was investigated that could be used in combat and whose final result was the 5.56 × 45mm NATO cartridge. In fact, other NATO countries were also developing and testing weapons that fire small caliber cartridges.

Many officers called for this new weapon to be light, reliable, accurate, and able to fire fully automatic. To the contest called to find the new assault rifle, the FN FAL, two heavier and improved versions of the Garand and the AR-10 were presented. The AR-10 had promise but was too green for the time, so its designer, Eugene Stoner, was encouraged to mature the design.

The weapon ultimately chosen was the M14 rifle. When fired in automatic mode it was very inaccurate and uncontrollable. A lighter cartridge would allow more accurate automatic fire. In addition, many people in the Army did not think that it was the weapon that was needed, especially for fighting in scenarios where it was not fired at long distances. They also wanted a weapon that would allow the soldier to carry more ammunition and prevent it from running out in combat. In addition, by the 1950s the helicopter was beginning to require light infantry and airmobile forces.

The AR-15 rifle

The AR-15 assault rifle is an improved version of the AR-10 rifle and was a smaller caliber version of the aforementioned AR-10 combat rifle, designed by Eugene Stoner. At first it encountered several obstacles from the generals and staff of the Defense Advanced Research Projects Agency or DARPA (acronym in English), since they had a preference for larger calibers, in addition to the fact that it was the first assault rifle built with materials composites (steel, aluminum and plastic). The concept held promise for an army that saw the future in airmobility by equipping soldiers with a lighter assault rifle and ammunition. General Willard G. Wyman was aware of the research being done on munitions and the advantages it offered. the 5.56mm cartridge and asked Stoner to design the AR-15 to take advantage of those advantages.

The AR-15 waited two years to finally gain acceptance into the Armed Forces; in a demonstration, General Curtis LeMay ordered 8,500 AR-15s to replace aging M1 and M2 carbines in Strategic Air Command air base defense; however, Secretary of Defense Robert McNamara revoked the request.

This did not stop US special operations units and advisers in Vietnam from obtaining AR-15 rifles. In 1962, 1,000 XM177 E1/E2 rifles (actually AR-15s) were shipped for combat testing by American advisers and South Vietnamese Rangers. The American advisers verified the benefits of the AR-15 in combat and sent very favorable reports. The Pentagon wanted to arm the South Vietnamese Army with a modern weapon and the AR-15 offered advantages over the M14 by being better suited for weight and size. After multiple discussions in early 1963 a larger order for rifles was placed to equip the South Vietnamese Army.

A M16 of the first series.

That same year Britain placed an order for 5,000 AR-15 rifles. Their destination was the soldiers who were fighting in the jungles of Borneo against the Indonesian sponsored guerrillas. Soon the units that replaced their FAL rifles and Sterling submachine guns with these rifles sent in favorable reports, to the point that the 22 SAS Regiment decided to adopt the AR-15 as their standard weapon.

Finally, in 1963, the US Air Force was authorized to purchase 19,000 AR-15s, while the Army purchased 85,000 units of AR-15s. These early rifles were referred to as the XM16E1 as it was still in experimental form and had limited use, primarily jungle fighting. Part of the Army's order was planned to go toward equipping South Vietnam, replacing its old weaponry with modern rifles.

An American soldier shooting his M16A1 at the Vietnam War.

Vietnam

In 1963 the Special Forces won the backing of President Kennedy and Secretary of Defense McNamara to purchase AR-15 rifles. The airborne forces and the CIA followed them. All of them had their use in Vietnam in mind. Thus the purchase of tens of thousands of AR-15s had finally been achieved. When the AR-15s were introduced as a replacement for the M14, they were given the military designation M16. Because the M14 had shown itself to be inferior to the AK-47 in the first combats, the M16 was very well received, and its incorporation was even publicly promoted by General Westmoreland as quickly as possible. So an order was quickly passed to Colt in 1966 for the purchase of 850,000 M16s to equip the US Army and its allies.

The AR-15 design however was botched at this point by the Pentagon bureaucracy, which insisted on militarizing its design, introducing changes to the XM16E1 rifles purchased by the US Army, which ended with an investigation by the Congress in 1967 due to complaints from soldiers. An officer, bypassing the chain of command, wrote a letter to a senator who, upon investigating what was happening, pulled the necessary levers for everything to change.

Comparison of M16 and AK-47.

South Vietnamese soldiers armed with M16 rifles during the Tet Offensive, 1968.

The changes made to the new design created a weapon that was a nightmare to maintain and often suffered outages in combat. To begin with, the army decided to introduce a new cartridge whose propellant charge left abundant residues. They also introduced changes to the barrel and chamber, which accelerated corrosion and wear and tear on the M16 due to the humid conditions of Vietnam and combat use. Early in the Vietnam War the M16 acquired a dismal reputation due to the numerous jamming that M16s suffered in combat, when fired casings got stuck. To aggravate the problem, the Army neither taught soldiers how to clean the weapon nor distributed cleaning equipment to them, since the manufacturer informed that it was not necessary. Dirty weapons were constantly jamming, which for many in combat was a certain doom. At the most unforeseen moment it could get stuck (and, in fact, it used to) giving the user the need to shoot with his auxiliary weapon or with another one provided by his companions. It was not uncommon for it to get to the point that many Marines would put down their M16s and fight with captured enemy weapons (usually AK-47 based models). Over time, cleaning kits were delivered and soldiers were instructed in their use, although even before that, the case of Marines who tried to solve the problem was seen using toothbrushes to clean the residue and dirt inside. of their rifles, although this was not enough due to the other flaws of those M16 series. In the course of the conflict, stronger and more durable versions were manufactured, which included improvements.

Early models only had 20-round magazines, which was a disadvantage compared to the ironically older Soviet AK-47 and Chinese Type 56 rifles. Another complaint was the shape of the flame arrester, which made movement in the jungle difficult, since it caught on the vegetation.

An American Marine with his M16A1 during the Saigon Fall.

Improvements

With the introduction of a new type of cartridge and improvements, the M16 gradually increased its reliability. In 1967 Colt factories produced about 45,000 units per month of the M16A1. In the Tet Offensive of 1968 the power of the product of improvements was made clear. The National Front for the Liberation of Vietnam began to respect the M16 due to the heavy casualties it suffered, which was also helped by the South Vietnamese Army and other allied armies replacing their old weapons with the M16. Towards the end of the Vietnam War by April 1975, an estimated 950,000 M16 and M16A1 rifles had been supplied to the US and Allied militaries. As for the South Vietnamese Army, the M16 rifle was reserved primarily for US units, with small quantities initially issued to the South Vietnamese.

By 1970, cleaning kits had already been included in the rifle, instructions were included for soldiers on how to keep the rifle clean, and 30-round magazines were also introduced.

In 1977 NATO began to study adopting the 5.56 mm caliber. as standard. In 1980, during NATO trials to select new 5.56mm ammunition, the M16A1 proved much more reliable than the other weapons during firing.

The M16A1 was exported to many western armies and used in combat in the Civil War in El Salvador, the Lebanon War, as well as in conflicts in which the British Army took part (Malvinas, Oman or Aden).

M16A1

The US Army XM16E1 was essentially the same weapon as the M16 with the addition of a forward assist and corresponding notches in the bolt carrier. The M16A1 was the production model completed in 1967 and was produced until 1982.

To address issues raised by the XM16E1's test cycle, an enclosed birdcage flash suppressor replaced the XM16E1's three-prong flash suppressor that caught on twigs and leaves. Various other changes were made after numerous issues on the field. Cleaning kits were developed and issued while barrels with chrome chambers and later fully lined bores were introduced.

With these and other changes, the malfunction rate slowly decreased, and new soldiers were generally unfamiliar with teething problems. A rib was built into the side of the receiver on the XM16E1 to help prevent accidentally pressing the magazine release button while the ejection port cover is being closed. This rib was later extended on production M16A1s to help prevent the magazine release from being inadvertently depressed. The hole in the stud that accepts the cam pin has been crimped in on one side such that the cam pin cannot be inserted with the stud installed backwards, which would cause failure to eject until it is inserted. correct. The M16A1 saw limited use in training capabilities until the early 2000s, but is no longer in active service with the US, although it remains standard issue in many militaries around the world.

M16A2

Development of the M16A2 rifle was originally requested by the United States Marine Corps as a result of combat experience in Vietnam with the XM16E1 and M16A1. It was officially adopted by the Department of Defense as the "US Rifle, 5.56mm, M16A2" in 1982. The Marines were the first branch of the US Military to adopt it, in the early and mid-1980s, with the United States. The military followed suit in the late 1980s.

Modifications to the M16A2 were extensive. In addition to the new STANAG 4172 5.56×45mm NATO chambering and accompanying rifling, the barrel was made with a greater thickness at the front of the front sight, to resist flexing in the field and allow for a longer period. longer. of sustained heat without overheating. The rest of the barrel was kept in the original thickness to allow the installation of the M203 grenade launcher. Added a new adjustable rear sight, allowing the rear sight to be dialed in for specific range settings between 300 and 800 meters to take full advantage of the ballistic characteristics of the new SS109 rounds and allow for windage adjustments without the need for a tool or cartridge.The reliability of the weapon also allowed it to be widely used in the special operations divisions of the Marine Corps. The flash suppressor was again modified, this time to be closed at the bottom so it would not kick up dirt or snow when fired from the prone position and acts as a recoil compensator.

The foregrip has been changed from the original triangular shape to a round one, which is better suited to smaller hands and could be adapted to older models of the M16. The new forends were also symmetrical, so gun shops don't need to separate right and left hand refills. The forend retaining ring was tapered to make it easier to install and remove the forends. Added a middle finger notch to the pistol grip, as well as more texture to improve grip. The stock was lengthened 5 ⁄ 8 inches (15.9 mm). The new stock became ten times stronger than the original due to advances in polymer technology since the early 1960s. The original M16 stocks were made of phenolic resin impregnated with cellulose; the new stocks were designed from DuPont Zytel glass-filled thermosetting polymers. The new stock featured a fully textured polymer butt plate for better shoulder grip, and retained a panel to access a small compartment within the stock, often used to store a basic cleaning kit. The heavier bullet reduces muzzle velocity from 3,200 feet per second (980 m/s) to approximately 3,050 feet per second (930 m/s).

The A2 uses faster 1:7 twist rifling to properly stabilize the 5.56×45mm NATO L110/M856 tracer ammunition. A worn snare deflector was incorporated into the upper receiver immediately behind the ejection port to prevent snares from hitting left-handed users. The action was also changed, replacing the fully automatic setting with a three-round burst setting. When using a fully automatic weapon, inexperienced troops will often hold down the trigger and "spray" the gun. when they are under fire. The US Army concluded that three-shot groups provide an optimal combination of ammunition conservation, accuracy, and firepower. The USMC has retired the M16A2 in favor of the newer M16A4; some M16A2s remain in service with the US Army Reserve and National Guard, Air Force, Navy, and Coast Guard.

M16A3

The M16A3 is a modified version of the M16A2 adopted in small numbers by the US Navy SEAL Seabee and Security units. [183] It features the M16A1 firing group that provides "safe" 34;, "semi-automatic" and "fully automatic" instead of "safe", "semi-automatic" and "burst" from A2. Otherwise it is externally identical to the M16A2.

M16A4

The M16A4 is the fourth generation of the M16 series. It is equipped with a removable carry handle and a full-length quad Picatinny rail for mounting optics and other ancillary devices. The FN M16A4, utilizing safe/semi/burst selective fire, became standard issue for the US Marine Corps.

Military rifles are also equipped with a Knight's Armament Company M5 RAS handguard, which allows for mounting vertical grips, lasers, tactical lights, and other accessories, coining the designation M16A4 MWS (or Modular Weapon System) on US Army Field Manuals [184]

Colt also produces M16A4 models for international purchases:

• R0901 / NSN 1005-01-383-2872 (secure / semiautomatic)
• R0905 (Sure / Semi/Ráfaga)

A study of significant changes to Marine M16A4 rifles published in February 2015 described several new features that could be added from inexpensive and readily available components. Those features included: a muzzle compensator in place of the flash suppressor to control recoil and allow for faster follow-up shots, though at the cost of noise and flash signature and possible overpressure in close quarters; a heavier and/or free-floating barrel to increase accuracy from 4.5 MOA (minute(s) of angle) to potentially 2 MOA; changing the reticle on the rifle's combat optics from a chevron shape to the semicircle with a dot in the center used on the M27 IAR's Squad Day Optic so as not to obscure the target at long range; use a trigger group with a more consistent pulling force, including a reconsideration of the ability to explode; and the addition of ambidextrous charging handles and bolt releases for easier use with left-handed shooters.

In 2014, Marine Corps units were issued a limited number of adjustable stocks instead of the traditional fixed stocks for their M16A4s to cater to smaller Marines who would have trouble comfortably reaching the trigger when wearing body armor. Adjustable Stock has been added as a standard authorized accessory, meaning units can use O&M funds to purchase more if needed.

The Marine Corps had long maintained the full-length M16 as its standard infantry rifle, but in October 2015 the switch to the M4 carbine as the standard weapon was approved, giving Marines of marina a smaller and more compact weapon. There are already enough M4s in inventory to re-equip all the units needed by September 2016, and the M16A4s will be moved to support non-infantry Marines.

News

In the 1980s the M16A2 version was created to meet the request for improvements to the M16A1 taking into account the experiences of Vietnam. This version only has semi-auto and short burst (three shots) mode. The barrel is rifled to use both the 5.56mm NATO SS-109 ammunition, as well as earlier types of bullets of the same caliber. The stock, pistol grip, and fore-end were made of a stronger plastic material.

The United States currently uses the M16A3 and M16A4, more modern than the M16A2, which was the improved version of the M16A1, with a series of features that make it an improved weapon, such as the new flash suppressor, the reinforced forend and textured for greater support by the shooter, etc. Another novelty of the A2 version is that it can fire in two ways, semi-automatic or in a short burst (three shots); This is due to the difficulty many soldiers have in controlling their weapons when firing in automatic mode, since, in the excitement of combat, they empty their magazines in a few seconds. Although currently the M16A3 is the only one in the series that fires in automatic mode.

Production

The M16 is one of the most widely manufactured 5.56mm caliber rifles in the world. Currently, the M16/M4 system is in use by 15 NATO countries and more than 80 countries in the world. Together, the United States and Canada (in this country called the Diemaco C7) have produced more than eight million units, with approximately 90% still in operation.

In United States service, the M16 primarily replaced the M14 series rifle, M1 Garand, and M1 carbine as the standard infantry rifle, and to a lesser extent, some uses of the Browning Automatic Rifle. The M14 is still in service in the United States, but not as a standard service rifle; It is now only used as a Sniper Rifle, Designated Marksman Rifle, and various smaller niche areas.

Users

In addition to the United States (the country of origin), users of the M16 rifle and its variants include:

• Afghanistan
• Albania
• Argentina
• Brazil
• Bolivia
• Colombia
• Chile
• Mexico
• Peru
• Israel
• Iraq
• Italy
• Jamaica
• Japan
• Venezuela
• Paraguay
• El Salvador

Summary

The Colt 603 was the definitive model of the M-16, with initial problems fixed, and along with the XM-16 it was the most common in Vietnam.