|Rifle, Caliber 5.56 mm, M16|
From top to bottom: M16A1, M16A2,
|Place of origin||United States|
|Used by||See Users|
|No. built||c. 8 million|
|Mass||6.37 lb (2.89 kg) (unloaded) |
7.5 lb (3.40 kg) (loaded)
|Length||39.5 in (1,003 mm)|
|20 in (508 mm)|
|700–950 rounds/min cyclic sustained |
45–60 rounds/min semi-automatic
|3,150 ft/s (960 m/s) (|
|Effective firing range||550 m (601 yd) (point target) |
800 m (875 yd) (area target)
|Maximum firing range||3,600 m (3,937 yd)|
20-round detachable box magazine:
0.211 lb (96 g) empty / 0.738 lb (335 g) full
30-round detachable box magazine:
0.257 lb (117 g) empty / 1.06 lb (480 g) full)
Beta C-Mag 100-round double-lobed drum:
2.20 lb (1,000 g) empty / 4.81 lb (2,180 g) full)
The M16 rifle, officially designated Rifle, Caliber 5.56 mm, M16, is a family of
In 1964, the M16 entered US military service and the following year was deployed for
In 1983, the US Marine Corps adopted the M16A2 rifle and the US Army adopted it in 1986. The M16A2 fires the improved
The M16 has also been widely adopted by other armed forces around the world. Total worldwide production of M16s has been approximately 8 million, making it the most-produced firearm of its 5.56 mm caliber. The
In 1928, a U.S. Army 'Caliber Board' conducted firing tests at
However, senior American commanders having faced fanatical enemies and experienced major logistical problems during WWII and the Korean War, insisted that a single powerful .30 caliber cartridge be developed, that could not only be used by the new automatic rifle, but by the new
The U.S. Army then began testing several rifles to replace the obsolete M1 Garand. Springfield Armory's T44E4 and heavier T44E5 were essentially updated versions of the Garand chambered for the new 7.62 mm round, while
The first confrontations between the
As a result, the Army was forced to reconsider a 1957 request by General
This request ultimately resulted in the development of a scaled-down version of the
In 1958, the Army's
Combat Developments Experimentation Command ran experiments with small squads in combat situations using the M14, AR-15, and another rifle designed by Winchester. The resulting study recommended adopting a lightweight rifle like the AR-15. In response, the Army declared that all rifles and machine guns should use the same ammunition, and ordered full production of the M-14. However, advocates for the AR-15 gained the attention of Air Force Chief of Staff General
Throughout 1962 and 1963, the U.S. military extensively tested the AR-15. Positive evaluations emphasized its lightness, "lethality", and reliability. However, the
In January 1963, Secretary of Defense Robert McNamara concluded that the AR-15 was the superior weapon system and ordered a halt to M14 production. In late 1963, the Defense Department began mass procurement of rifles for the Air Force and special Army units. Secretary McNamara designated the Army as the procurer for the weapon with the Department, which allowed the Army ordnance establishment to modify the weapon as they wished. The first modification was the additions of a "manual bolt closure," allowing a soldier to ram in a round if it failed to seat properly. The Air Force, which was buying the rifle, and the Marine Corps, which had tested it both objected to this addition, with the Air Force noting, "During three years of testing and operation of the AR-15 rifle under all types of conditions the Air Force has no record of malfunctions that could have been corrected by a manual bolt closing device." They also noted that the closure added weight and complexity, reducing the reliability of the weapon. Colonel Howard Yount, who managed the Army procurement, would later state the bolt closure was added after direction from senior leadership, rather than as a result of any complaint or test result, and testified about the reasons: "the M-1, the M-14, and the carbine had always had something for the soldier to push on; that maybe this would be a comforting feeling to him, or something."
After modifications, the new redesigned rifle was subsequently adopted as the M16 Rifle. "(The M16) was much lighter compared to the M14 it replaced, ultimately allowing soldiers to carry more ammunition. The air-cooled, gas-operated, magazine-fed assault rifle was made of steel, aluminum alloy and composite plastics, truly cutting-edge for the time. Designed with full and semi-automatic capabilities, the weapon initially did not respond well to wet and dirty conditions, sometimes even jamming in combat. After a few minor modifications, the weapon gained in popularity among troops on the battlefield."
Despite its early failures the M16 proved to be a revolutionary design and stands as the longest continuously serving rifle in US military history. It has been adopted by many US allies and the
M16s were produced by Colt until the late 1980s, when FN Herstal began to manufacture them.
In July 1960, General
The damage caused by the 5.56 mm bullet was originally believed to be caused by "tumbling" due to the slow 1 turn in 14-inch (360 mm) rifling twist rate. However, any pointed lead core bullet will "tumble" after penetration in flesh, because the center of gravity is towards the rear of the bullet. The large wounds observed by soldiers in Vietnam were actually caused by bullet fragmentation created by a combination of the bullet's velocity and construction. These wounds were so devastating, that the photographs remained classified into the 1980s.
However, despite overwhelming evidence that the AR-15 could bring more firepower to bear than the M14, the Army opposed the adoption of the new rifle. U.S.
In January 1963, Secretary McNamara received reports that M14 production was insufficient to meet the needs of the armed forces and ordered a halt to M14 production. At the time, the AR-15 was the only rifle that could fulfill a requirement of a "universal" infantry weapon for issue to all services. McNamara ordered its adoption, despite receiving reports of several deficiencies, most notably the lack of a
After modifications (most notably, the charging handle was re-located from under the carrying handle like AR-10 to the rear of the receiver), the new redesigned rifle was renamed the Rifle, Caliber 5.56 mm, M16. Inexplicably, the modification to the new M16 did not include a chrome-plated barrel. Meanwhile, the Army relented and recommended the adoption of the M16 for jungle warfare operations. However, the Army insisted on the inclusion of a
In November 1963, McNamara approved the U.S. Army's order of 85,000 XM16E1s; and to appease General LeMay, the Air Force was granted an order for another 19,000 M16s. In March 1964, the M16 rifle went into production and the Army accepted delivery of the first batch of 2,129 rifles later that year, and an additional 57,240 rifles the following year.
In 1964, the Army was informed that
In March 1965, the Army began to issue the XM16E1 to infantry units. However, the rifle was initially delivered without adequate cleaning kits or instructions because Colt had claimed the M16 was self-cleaning. As a result, reports of stoppages in combat began to surface. The most severe problem was known as "failure to extract"—the spent cartridge case remained lodged in the chamber after the rifle was fired. Documented accounts of dead U.S. troops found next to disassembled rifles eventually led to a Congressional investigation.
We left with 72 men in our platoon and came back with 19, Believe it or not, you know what killed most of us? Our own rifle. Practically every one of our dead was found with his (M16) torn down next to him where he had been trying to fix it.
In February 1967, the improved XM16E1 was standardized as the M16A1. The new rifle had a chrome-plated chamber and bore to eliminate corrosion and stuck cartridges and other, minor, modifications. New cleaning kits, powder solvents and lubricants were also issued. Intensive training programs in weapons cleaning were instituted including a