View Full Version : History of the M16

22nd Oct 2001, 05:31 PM
Long read, but I think you'll enjoy it:

The United States Rifle, Caliber 5.56mm, M16 series family of weapons began its development from the research conducted by the U.S. Army's Operations Research Office(ORO), created at Johns Hopkins University in September 1948, with the purpose of increasing the effectiveness of military operations. The ORO's first assignment was to determine how to create better body armor to protect troops in combat. The ORO began conducting its research by questioning infantrymen who fought in Korea. Around 87% of the 602 infantrymen surveyed stated 95% of their firing was at targets within 300 yards, a limitation of terrain and other environmental conditions. Many reported most of their kills occurred at less than 100 meters. The research also showed that wounds and combat deaths were just as likely to happen from unaimed, reactive firing as from deliberate, aimed fire. Using these finding, ORO stated a .22 caliber rifle firing a salvo of projectile with a controlled dispersion pattern would give the desired effect at ranges up to 300 meters. It should be noted this research was being conducted under a cloud of secrecy at the same time Army Ordnance personnel were arguing with their British counterparts on the merits of .28 and .30 caliber projectiles. Please note ORO had reached the same basic conclusion German military planners did over a decade earlier when developing their 7.92mm x 33 Kurz cartridge. With these findings, Ordnance engineers conducted Project SALVO between 1953 to 1957.

During Project SALVO's tenure, several innovative designs appeared: a duplex cartridge using two projectiles stacked one above the other and Earle Harvey designed a trajectory altering device to cause a bullet to take a slightly different path than the previously fired bullet. After Project SALVO concluded in 1957, the Continental Army Command(CONARC) asked Winchester Repeating Arms and the ArmaLite Division of the Fairchild Engine and Airplane Corporation if they cared to develop a high-velocity .22-caliber rifle. Enter Eugene Stoner...


Eugene Stoner(1922 - 1997) began designing rifles upon his discharge from the Marine Corps after World War II. He had developed several designs, but had not achieved true commercial success. His latest design was called the AR-10, introduced just as the final testing of the T44E4 and T48 rifles was being conducted.
The AR-10, a 7.62mm NATO caliber rifle, was unable to compete directly with those two designs, but it did sell in very small quantities to countries like Sudan and Portugal two years later. But the AR-10 did catch the eye of U.S. Army General Willard G. Wyman, who asked Stoner and ArmaLite to design a high-velocity .22-caliber rifle. The new design had to meet the following requirements, but the last requirement showed a partial failure to fully understand the findings of the ORO report:

Have a 20 round magazine.
Weigh less than 6 pounds loaded.
Have selective fire capability.
Fire a round able to penetrate a standard steel helmet, body armor or 3.4mm-thick steel plate out to 500 meters.

With these requirements in mind, Stoner began. To meet the 500 meter standard, Stoner had the Remington Arms Company increase the capacity of their .222 Remington cartridge to fire a 55-grain bullet at 3300 feet per second. With the new round, known as the .223 Remington, Stoner started work on the rifle. His first attempt was of a conventional design that was uncontrollable when fired fully-automatically, so he created a scaled-down AR-10.


The new Stoner rifle took ideas and other smaller details from many rifles and combined them into one design: the locking system from the M1941 Johnson rifle, the use of a hinged receiver and the buffer system from the FAL, the straight in-line stock from the T-25 and the direct gas system of the Swedish M42 Ljungman rifle, which eliminated several moving parts and made the rifle simpler to operate and cheaper to manufacture. Because the new cartridge allowed him to use aluminum alloys and plastics, Stoner's new rifle, the AR-15, weighed only 6.35 pounds(2.89 kilograms) empty. But Stoner also made some mistakes. Stoner did not feel a need to have the AR-15's barrel chrome-plated, especially since ArmaLite didn't possess the capability to plate the barrel, but Army research after World War II had shown the benefits of having a chrome-plated barrel and chamber on rifles designed for automatic fire and Army declared after the M14's adoption that all subsequent rifles would have chrome-lined barrel and chambers. In developing the AR-15's cartridge, Stoner used a type of gunpowder known as IMR powder. With the IMR powder, the AR-15 was highly reliable, but the Army was now in the process of converting to the use of ball type powder in its cartridges, which was cheaper to produce and had wholly different ballistic characteristics. The only major problem with the prototype AR-15 design was that it wasn't fully developed before Army testing began nine months later on 31 March 1958. Ordnance engineers and ArmaLite designers didn't see eye-to-eye from the start, but the AR-15 proved to be a workable design and the Infantry Board report stated a fully-developed AR-15 would be a suitable replacement for the M14 rifle. But later tests showed some problems. Rainwater in one AR-15 barrel cause it to burst when fired. Stoner redesigned and strengthened the barrel, but Ordnance engineers said the problem still remained, due to the .22-caliber size of the barrel. It was also at this time when Stoner learned several of his rifles were set to the Army Arctic Test Board and reliability problems were noted there. Stoner went to Alaska to find the problems with the AR-15 were caused by Army personnel, who disassembled the rifle and reassembled it improperly. Stoner asked for a new test trial because of the way the AR-15 had been mishandled. The Army then began to stonewall Stoner over the suitability of the AR-15, but said if the AR-15 was built to fire a new .258 caliber round which the Ordnance department now stated was the best cartridge, it may be suitable. Additionally, the Army Chief of Staff, General Maxwell Taylor, did not favor the AR-15 and recommended continued production of the M14. Because of this treatment and its desire to recoup its $1.45 million development expense, Fairchild sold its rights to the AR-15 to Colt's Patent Firearms Manufacturing Company for $75,000 cash and a 4.5% royalty on subsequent rifle sales in December, 1959. In 1960, ArmaLite was reorganized and Stoner left ArmaLite during this reorganization.

Colt now began gambling its corporate future on the AR-15 with a bold, double-pronged attack. First, Colt began attacking the M14 rifle and secondly, it looked to influence other high-ranking DoD officials. One of the first officials to be spoken with was General Curtis LeMay, then Air Force Vice Chief of Staff. On 4 June 1960, a demonstration in front of LeMay convinced him to purchase 8500 rifles to replace M2 carbines used by Strategic Air Command sentries. Colt also approached the Advanced Research Projects Agency(ARPA). ARPA thought highly of the AR-15 and bought 1000 rifles for use by South Vietnamese troops in the early summer of 1962. During this "trial by fire" period, American military advisors working with South Vietnamese troops filed some remarkable field reports about the AR-15's capabilities:

On 16 June 1962, one platoon from the 340 Ranger Company was on an operation...and contacted three armed Viet Cong in heavily forested jungle. Two VC had carbines, grenades, mines and one had a sub-machinegun. At a distance of approximately 15 meters, one Ranger fired an AR-15 full automatic hitting one Viet Cong with three rounds in the first burst. One round in the head took it completely off. Another in the right arm, took it completely off too. One round hit him in the right side, causing a hole about five inches in diameter...it can be assumed that any one of the three wounds would have caused death.

The ARPA report served as the basis for a cost-effectiveness study between the AR-15 and the M14, which stated the AR-15 would give U.S. infantrymen a firepower advantage over their AK-47-armed Soviet counterparts. Secretary of Defense Robert McNamara now had two conflicting views: the ARPA report favoring the AR-15 and the Army's position on the M14. Even President John F. Kennedy expressed concern, so McNamara ordered Secretary of the Army Cyrus Vance to test the M14, the AR-15 and the AK-47. The Army's test report stated only the M14 was suitable for Army use, but Vance wondered about the impartiality of those conducting the tests and ordered the Army Inspector General to investigate the testing methods used. The Inspector General report stated Army testers showed undue favor to the M14. Colt now began to press its advantage using the civilian media to condemn the M14 and in their overzealous marketing efforts, Colt stated the AR-15 didn't require as much maintenance as normal rifles. As such, when the Department of Defense began buying the AR-15, no cleaning kits were procured. With political pressure mounting, McNamara ordered M14 production halted on 23 January 1963.
On 4 November 1963, Colt received an order for the purchase of 85,000 XM16E1s for the Army and 19,000 M16s for the Air Force. In 1964, a new Small Arms Weapons Systems(SAWS) study was done by the Army to determine which weapons suited the Army's needs between 1967 and 1980. The new study favored the AR-15 so much it was now called the 5.56mm M16.18 The Air Force now got into the game by adopting the AR-15 as the United States Rifle, Caliber 5.56mm, M16 on 8 February 1964. At the same time, the Army named the XM16E1 as a limited standard.19 The XM16E1 differed from the M16 by the addition of a bolt-closure device, known as a forward assist. Colt, the Air Force, the Marine Corps and Eugene Stoner all agreed this device complicated the rifle and added about $4.50 to its procurement cost, but the Army won on this point and three years later adopted the XM16E1 as the United States Rifle, Caliber 5.56mm, M16A1 on 28 February 1967.20 On 16 June 1966, Colt was awarded a contract for nearly 840,000 rifles for $91.7 million, assuring the M16's future. But between 1965 and 1967, several major problems, centering on the direct gas action and the lack of maintenance equipment, occurred with the M16 in combat because there was no one entity to manage the overall production process of the M16.

The use of ball gunpowder left a very sticky residue in the barrel and the gas tube of the M16. Since the barrel wasn't chrome-plated and no cleaning equipment and/or lubricants were available, it hardened quickly and soon made the rifle inoperable. The residue also caused spent casings to become stuck in the chamber and the rifle suffered a rim shear extraction failure, where the bolt's extractor tore off a portion of the end of the spent casing, leaving the rest of the case stuck in the chamber. Because of the ball gunpowder's ballistic characteristics and the rifle's buffer's light weight, the M16 fired fully automatically with a cyclic rate of between 850-1000 rounds per minute, well in excess of the normal 750-850 rounds per minute. Compounding this comedy of errors was the lack of training and instruction given to those troops who were issued the M16.

Beginning on 15 May 1967, the problems were investigated by a Congressional subcommittee, headed by Representative Richard Ichord, a Democrat from Missouri. After seeing the M16 malfunction firsthand during tests at Fort Benning and Camp Pendleton and traveling to Vietnam to assess the problems, the Ichord Subcommittee report, issued in late June, 1967, stated "the much-troubled M16 rifle is basically an excellent weapon whose problems were largely caused by Army mismanagement." To correct the M-16's fouling problems, the formulation of the ball gunpowder used in the 5.56mm M193 Ball cartridge was changed by reducing the level of calcium carbonate(CaCO3 - limestone, used as an acid neutralizer to extend shelf life) from 1% to .25%, less than half the amount shown to clog the M16's gas tube. A new heavier weight buffer was developed to reduce cyclic rates back to normal. A cleaning kit was developed, along with a new buttstock able to store the cleaning kit in the rifle. Finally, a massive training program on how to properly maintain the M16 was instituted and made use of a rifle maintenance comic book. With the major operational problems finally solved, the next most pressing problem was how to get more rifles into the hands of troops needing them. Two additional contractors, Harrington & Richardson and the Hydramatic Division of General Motors Corporation, were awarded contracts to produce the M16/M16A1. With the operational and production problems resolved, the M16/M16A1 began to operate with great reliability.

As American involvement in the Vietnam conflict intensified, several variants of the M16 appeared, including a short-lived sniper rifle. As early as 1965, Colt engineers first designed a carbine version of the M16, called the CAR-15, using a collapsible, sliding buttstock and a 10"(254mm) long barrel, with a long flash hider/muzzle compensator to control the loud report and huge muzzle flash of the weapon. Combat use of the test rifles, called the XM177 in the Air Force version without the forward assist and the XM177E1 by the Army, showed it was very well suited in its role. Special Forces units especially liked its light weight. After experience showed some erratic performance with most ammunition types, the barrel was lengthened to 11.5"(292mm) and renamed the XM177E2 by the Army and the GAU-5/A/A in the Air Force version without the forward assist. But this version ultimately proved to not be viable enough for the military and further development was stopped.

The M16/M16A1 soldiered on for the remainder of the Vietnam War without problem. And on 13 March 1970, the U.S. Army shocked other NATO nations by stating all U.S. forces assigned to NATO would be equipped with the M16/M16A1. The British military was highly vocal in voicing its anger after being thrashed by American Ordnance personnel into adopting the 7.62mm NATO round because their .280 caliber round wasn't effective enough nearly twenty years earlier. And now the American Army was adopting an even smaller round!!!

The next major design change made to the M16/M16A1 family occurred after a series of NATO-sponsored tests were conducted to determine what type of ammunition would be needed after 1980. The new design included the following design changes:

Barrel with a rifling twist of 1:7 and with a heavier diameter near the muzzle.
Stronger, more durable, more ergonomic buttstock.
Handguards now used an interchangeable top-and-bottom design, not separate left/right halves.
Rear sight made adjustable for windage and elevation.
Flash hider redesigned to give less muzzle flip and dust signature when fired.
Fully automatic mode replaced with a three round burst, to conserve ammunition in combat.

During the Summer of 1981, the M16A1E1 was tested very thoroughly and was type-classified as the M16A2.

After the military conflicts in Panama, the Persian Gulf and Somalia, the need for a shorter version of the M16A2 again appeared. Colt engineers shortened the barrel back to 14.5", recontoured the barrel to mount the M203 grenade launcher and added a modified version of the collapsible, sliding buttstock of the earlier XM177 series rifle.
They also created a new upper receiver using a modular sight mounting system for use on a sub-variant. In August, 1994, both variations were adopted. The United States Carbine, Caliber 5.56mm NATO, M4 uses the new barrel and collapsible buttstock, but was first issued with the standard M16A2 upper receiver and sights to streamline production, though it now is made with the new modular upper receiver. The M4 could be fired either semi-automatically or with three round bursts. The United States Carbine, Caliber 5.56mm NATO, M4A1 uses the new barrel and collapsible buttstock and the new upper receiver for mounting a wide variety of sights, including night vision and infrared aiming lasers, as well as the standard sights on a detachable handle, but it is also capable of fully-automatic fire, like the M16A1. The M4 and M4A1 have been produced by Colt and by Bushmaster Arms. Additionally, the military has begun procuring both the M16A3 and M16A4. The M16A3 and the M16A4 are identical to the M16A2, but both have the modular upper receiver. The M16A3 is capable of fully-automatic fire, like the M16A1, while the M16A4 uses the M16A2's three-round burst mechanism. Additonally, several types of optical sights have been developed for the modular upper. The new sights include a "red dot," close combat sight, much like civilian IPSC-style competitors use to quickly index to a target and an infrared thermal sight, to allow a soldier to see a target at night from body heat.

Taken from here. (http://www.wwa.com/~dvelleux/m16rifle.html)

22nd Oct 2001, 09:02 PM
Did anyone read this or was it too long? :p

22nd Oct 2001, 09:07 PM
I read some of it..... mainly the parts about Stoner....

Any gun made by a dude named Stoner must be good.... :D

22nd Oct 2001, 10:23 PM
Nice nice read!

We need the M16 A3! ;)

22nd Oct 2001, 11:02 PM
I was reading for so long that Dank's magic dragon stopped smoking!

22nd Oct 2001, 11:20 PM
Rainwater in one AR-15 barrel cause it to burst when fired.

you always wonder exactly how they figured thing like this out... and how badly the guy who burst his barrel was fu<i></i>cking up. i read about the development of ejection seats for jet fighters, and they used 20mm cannon shells to eject the seat away from the aircraft. however, this wasn't fast enough, so they upgraded to a 30mm cannon shell. when they tested the 30mm though, the pilot who ejected had his spine folded up like an accordion, because the shell was so powerful.... ouch.:eek2:

23rd Oct 2001, 12:05 AM
They also created a new upper receiver using a modular sight mounting system for use on a sub-variant. In August, 1994, both variations were adopted. The United States Carbine, Caliber 5.56mm NATO, M4 uses the new barrel and collapsible buttstock, but was first issued with the standard M16A2 upper receiver and sights to streamline production, though it now is made with the new modular upper receiver. The M4 could be fired either semi-automatically or with three round bursts. The United States Carbine, Caliber 5.56mm NATO, M4A1 uses the new barrel and collapsible buttstock and the new upper receiver for mounting a wide variety of sights, including night vision and infrared aiming lasers, as well as the standard sights on a detachable handle, but it is also capable of fully-automatic fire, like the M16A1. The M4 and M4A1 have been produced by Colt and by Bushmaster Arms.

Great deal of misinformation here.

The M4 was developed from the M16A1 carbine which was an XM177E2 with a 14.5 inch barrel and an M16A1 flashhider built back around 1966.

Never very popular in the US military, the only takers were the USAF and the USMC. Now, in 1983 the marines requested for a replacement for the M16A1 carbine.

Colt simply took the M16A1 carbine design and added all the bells and whistles the M16A2 has. Also adding a 4 position(3 actually tubular stock). Design was finalised in 1985.

The standard M4 is also known by another name: The M16A2 carbine. The design was adopted by the US Army(they're always behind the USAF and Navy for some reason aren't they?) in August 1994.

Bushmaster only supplied 4,000 M4s to the US Army to meet the demand during the gulf war. For some reason, they aren't allowed to fill any further military contracts. Although LE is OK. Weird eh?

23rd Oct 2001, 01:12 AM
ShakKen, always has to find flaws in peoples stories :D
but i actually picked up on the M4 being developed from the M16A1 as the XM177E2 :) .