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What is the AR-15?

The civilian version of the M-16, called the AR-15, is a single-shot per trigger pull weapon. The AR-15 is used by private citizens for everything from deer hunting to plinking at cans.

Any weapon which shoots automatically, more than one shot, without manual reloading, by a single function of the trigger, is a machinegun as defined in 26 U.S.C. 5845(b), the National Firearms Act (NFA). In addition, the definition of a machinegun also includes any combination of parts from which a machinegun may be assembled, if such parts are in possession or under the control of a person. An AR-15 type assault rifle which fires more than one shot by a single function of the trigger is a machinegun under the NFA. Any machinegun is subject to the NFA and the possession of an unregistered machinegun could subject the possessor to criminal prosecution. ATF has encountered various AR-15 type assault rifles such as those manufactured by Colt, E.A. Company, SGW, Sendra and others, which have been assembled with fire control components designed for use in M16 machineguns. The vast majority of these rifles which have been assembled with an M16 bolt carrier, hammer, trigger, disconnector and selector will fire automatically merely by manipulation of the selector or removal of the disconnector. Many of these rifles using less than these five M16 parts also will shoot automatically by manipulation of the selector or removal of the disconnector.

An assault weapon was defined under federal law as a semi-automatic [capable of being fired as fast as the operator can pull the trigger] assault pistol or rifle that can accept a detachable magazines and with two or more assault characteristics; or semi-automatic shotguns with two or more assault characteristics, including a pistol grip or thumbhole stock; folding stock or telescopic stock; flash suppressor or a threaded barrel capable of accepting a flash suppressor, bayonet mount, or grenade launcher.

The AR-15 is a semiautomatic assault weapon as defined in the Gun Control Act of 1968. 18 U.S.C. 921(a)(30). Under this law it waa generally unlawful to possess or transfer these firearms. 18 U.S.C. 922(v)(1). This prohibition, however, did not apply to any AR-15 that was lawfully possessed on or before Sept. 13, 1994. 18 U.S.C. 921(v)(2). This 1994 federal assault weapons ban expired in September 2004, and with it the prohibition against selling this type of semiautomatic firearm.

 

History of the M16/AR-15

The US Army long had a deeply entrenched and historical view which argued that carefully aimed, long-range rifle fire is superior to the high-volume but largely unaimed bursts of automatic weapons. Those who argued for aimed fire believed that good marksmanship and judicious control win battles and conserve ammunition.

Military historian S.L.A. Marshall found that only 4 out of 10 World War II veterans fired at the enemy. Retired Lieutenant Colonel Dave Grossman, in his book, On Killing: The Psychological Costs of Learning to Kill in War and Society, concluded that failing to fire at the enemy is a universal problem. He observes that humans have an deep aversion to harming others, and only tough, realistic training that conditions soldiers to kill relexively in combat can overcome this aversion, but even this is never completely effective. Even with such training, very few troops are mentally prepared to direct aimed fire at the enemy, preferring instead to spray bullets in the general direction of the enemy.

This is the basis of the argument that weapons with high volumes of fire would meet the wartime needs of the US military much better. At a time when the infantry of many armies is armed with sophisticated and fully automatic versions of assault rifles, US foot soldiers are equipped with the M-16, a one-pull, three-shot rifle.

The M-14 was the Army' s original choice to replace World War II-era M-1 and Browning Automatic rifles. The M14 was an unhappy compromise weapon, that satisfied virtually no one, least of all the men for whom it was intended. General dissatisfaction with the M14 and numerous studies led the Army to the development of a light weight weapon capable of firing a burst of small caliber bullets with a controlled dispersion pattern. Unfortunately, the M-14's follow-on initially fared little better.

The replacement for the M14 was originally designed by Eugene Stoner, of the ArmaLite Company, as the AR-15 around 1956. The AR-10 was conceived by Eugene Stoner as a 7.62mm Basic infantry rifle in 1955. At that time the Army was considering replacements for the M1 Garand. The AR-10 was stunningly different than any previous design. It was produced with aircraft grade aluminum receivers, and therefore weighed less than seven pounds. The stock and other furniture were plastic, while the T-44 and T-48 were of wood. The configuration of the rifle itself, with its integral carrying handle and charging handle distinctively mounted within it, sparked intense curiosity. In the end, the AR-10 wasn't able to catch up, and eventually lost out to the M-14 rifle in 1959.

Based on the AR-10, Army officials asked ArmaLite to develop a smaller version of the AR-10 in 1956. The ensuing rifle was called the AR-15. Army analysis of battlefield statistics from WWI, WWII and Korea, had shown that most kills from small arms occured at ranges of less than 300 yards. This suggested that the military should seriously consider lighter weight, higher capacity weapons. Seeking a novel cartridge suitable for a smaller caliber assault rifle, Eugene Stoner approached Winchester Corporation. The result was the small but powerful .223 Rifle Cartrdige -- high-velocity, light weight, low recoil, and capable of penetrating a helmet per US Army specifications.

Production of the AR-15 rifle was licensed to to Colt Manufacturing Company in 1959. Early Colt AR-15s, their magazines, and their operators manuals were marked with ArmaLite's name. Colt's retained the AR-15 designation on commercial rifles. To this day Colt's has a model designation with the letters AR, which stands for "ArmaLite".

The AR-15 was selectable for full and automatic fire. The AR-15 was to have had the same effective range as the M14 rifle, but it was most effective at a range of 215 yards (200m) or less. The M16 used a 5.56mm (.223 cal.) cartridge in 20- or 30-round magazines. To compensate for the reduced size of the 5.56 mm bullet, the AR-15 designers increased the velocity of the bullet so that it would have an adequate range and the flat trajectory needed for accurate aiming. The M16 bullet had a muzzle velocity (velocity on leaving the gun) of 980 meters per second as compared to 870 meters per second for the M14 rifle and 720 metres per second for the Soviet AK-47 7.62 mm rifle, while at a range of 100 meters the velocities of the three bullets were 830, 800, and 630 meters per second respectively.

The U.S. Air Force completed tests of the AR-15 in January 1961. The Air Force procured 8,500 rifles in 1961 and standardized the AR-15 in 1963. The weapon was first deployed to the Air Force's Air Police. The original AR-15 was designated the M16 in 1962.

The new rifle had the advantage from a military point of view of weighing one- fourth less than the M14, and the ammunition also was lighter, reducing the recoil against the soldier's shoulder and enabling a soldier to carry more rounds. As interest in the problems of counter-insurgency grew under the Kennedy administration in the early 1960s, the US military quietly bought several thousand AR-15s and sent them to Vietnam for testing in combat conditions.

In the Vietnam era, DARPA (then ARPA) gained acceptance for the AR-15 by sponsoring its demonstration in combat. Colt brought the weapon to DARPA in 1962. Through Project AGILE, DARPA purchased 1,000 AR-15s and issued them to combat troops in Southeast Asia for field trials, to prove that the high-velocity 5.56 mm round had satisfactory performance. The subsequent DARPA report, documenting the lethality of the AR-15, was instrumental in motivating the Secretary of Defense to reconsider the Army's decision and eventually adopt a modified AR-15 as the US military individual weapon of choice. Although opposed by the Ordnance Corps, the Armalite AR-15 was adopted by the Secretary of Defense as the 5.56mm M16 rifle.

Soon reports began appearing of the lethality of the new rifle. Unofficial reports said the AR-15's light bullet, travelling at 3,300 feet per second, did cartwheels as it penetrates living flesh, causing a highly lethal wound that looks like anything but a caliber .22 hole, the US magazine Army reported in August 1963. Two US Army doctors who evaluated AR-15 wounds at an Army hospital in South Vietnam in 1966 reported that while wounds inflicted at close range had small entrance and exit holes, those at larger ranges exhibited small entrance holes whereas the exit wound is a gaping, devastated area of soft tissue and even bone, often with loss of large amounts of tissue, with disintegration of the bullet and minute splattering of lead.

By 1963 US Army was purchasing the M16 for use in South East Asia and by various elite forces. The Army also ordered 85,000 rifles in 1963. An additional 35,000 were ordered in 1964, 100,000 in 1965, and 100,000 in 1966. These rifles were initially issued primarily to combat troops in the Dominican Republic and to Special Forces, Airborne, helicopter crews, Air Commando and other special category troops in Vietnam.

The M-16 was type classified standard A in 1965 and became the military's basic service rifle. By 1966 it was in widespread use. The M16 was called the "black rifle" and "Mattel toy" thanks to its appearance. Troops liked the light weight, but complained about insufficient range and lethality. While the M16 had been marketed as virtually "maintenance free, poor maintenance instructions (or even no instructions) and jungle climate together with the fouling-prone direct gas system caused trouble. Its high rates of fire in the jungle environment had a larger impact on increasing American morale than on actually inflicting enemy casualties. The move to high-velocity 5.56 mm was also subsequently adopted by the Israelis, the Soviets, and NATO allies. DARPA's most significant contribution to this program was its willingness to "think outside of the box" and try something new.

The AR-15 was redesignated by the US Army as the M16 rifle, and in 1967 the Army announced that it would be adopted as the standard infantry weapon for US Forces outside NATO. By 1978 the rifle had been exported to 21 countries and was being produced under licence in another three, with various other 5.56 mm rifles in production elsewhere.

Source- www.globalsecurity.org

History of the 5.56x45mm

The previous standard NATO round was the 7.62 × 51 mm, derived from the .300 Savage rifle cartridge and designed to replace the U.S. military's .30-06 Springfield rifle cartridge. At the time of selection, there had been criticism that the 7.62 mm round was too powerful for modern assault rifles, causing excessive recoil, and that the weight of the ammunition did not allow for enough "firepower" in modern combat.

The British had extensive evidence with their own experiments into an "intermediate" round and were on the point of introducing a .280 inch (7 mm) round. The FN company had also been involved. These concerns were effectively overruled by the US within NATO, and the other NATO nations accepted that standardization was more important at the time than selection of the ideal round. These concerns would prove to be valid and led to the development of the 5.56 cartridge.

During the late 1950s, ArmaLite and other U.S. firearm designers started their individual Small Caliber/High Velocity (SCHV) assault rifle experiments using the commercial .222 Remington cartridge. When it became clear that there was not enough powder capacity to meet U.S. Continental Army Command's (CONARC) velocity and penetration requirements, ArmaLite contacted Remington to create a similar cartridge with a longer case body and shorter neck. This became the .222 Remington Special. At the same time, Springfield Armory's Earle Harvey had Remington create an even longer cartridge case then known as the .224 Springfield. Springfield was forced to drop out of the CONARC competition, and thus the .224 Springfield was later released as a commercial sporting cartridge known as the .222 Remington Magnum. To prevent confusion with all of the competing .222 cartridge designations, the .222 Remington Special was renamed the .223 Remington. After playing with their own proprietary cartridge case design, the .224E1 Winchester, Winchester eventually standardized their case dimensions, but not overall loaded length, with the .222 Remington Special to create a cartridge known as the .224E2 Winchester. With the U.S. military adoption of the ArmaLite AR-15 as the M16 rifle in 1963, the .223 Remington was standardized as the 5.56 × 45 mm. However, the .223 Remington was not introduced as a commercial sporting cartridge until 1964.

During the 1970s, NATO members signed an agreement to select a second, smaller caliber cartridge to replace the 7.62 mm NATO. Of the cartridges tendered, the 5.56 mm was successful, but not the 5.56 mm loading (M193 Ball) as used by the U.S. at that time. Instead, the Belgian FN SS109 loading was chosen for standardization. The SS109 used a heavier bullet at a lower muzzle velocity for better long-range performance, specifically to meet a requirement that the bullet be able to penetrate through one side of a steel helmet at 600m. Some believe that this requirement has made the M855 less capable of fragmentation than the M193 as discussed below.

5.56 NATO vs .223 Remington

While the 5.56 mm and .223 cartridges are very similar, they are not identical. Military cases are made from thicker brass than commercial cases, which reduces the powder capacity (an important consideration for handloaders), and the NATO specification allows a higher chamber pressure. The 5.56 mm chambering, known as a NATO or mil-spec chambers, have a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet. The .223 chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof tested to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber (Rock River Arms)[1] or the Armalite chamber, which are designed to handle both 5.56 mm and .223 equally well.

Using commercial .223 cartridges in a 5.56-chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223-chambered gun due to the excessive lead.[2] Using 5.56 mil-spec cartridges (such as the M855) in a .223-chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and the SAAMI recommends against the practice.[3] Some commercial rifles marked as ".223 Remington" are in fact suited for 5.56 mm, such as many commercial AR-15 variants and the Ruger Mini-14, but the manufacturer should always be consulted to verify that this is acceptable before attempting it, and signs of excessive pressure (such as flattening or gas staining of the primers) should be looked for in the initial testing with 5.56 mm ammunition.[4]