AR-10

From Wikipedia, the free encyclopedia

AR-10
The AR-10 Rifle
Type	Service rifle
Place of origin	United States of America
Service history
In service	1958–1985 (Sudan); 1960-1976 (Portugal)
Used by	Guatemala, Sudan, Portugal, Italy, Cuba, Burma
Wars	Angola/Mozambique/Sudan/Dominican Republic/Portuguese Timor
Production history
Designed	1955-56
Manufacturer	Fairchild Armalite, Artillerie Inrichtingen (AI)
Produced	1956–1960
Number built	~10,000
Variants	Hollywood, Sudanese, Transitional, Portuguese, Carbine
Specifications
Weight	3.29-4.05 kg (7.25 - 8.9 lb)
Length	1050 mm (41 in)
Barrel length	528 mm (20.8 in)

Cartridge	7.62 × 51 mm NATO, 7.62 x 39 mm Soviet
Caliber	7.62 mm (.308 in)
Action	Gas-operated, rotating bolt
Rate of fire	700 round/min
Muzzle velocity	820 m/s (2,700 ft/s)
Effective range	630 m (700 yd)
Feed system	20-round detachable box magazine
Sights	Adjustable aperture rear sight, fixed "blade" front sight

The AR-10 is a gas operated selective-fire automatic rifle that fires 7.62 × 51 mm NATO (.30 cal.) ammunition. Designed by Eugene Stoner, the AR-10 operates on the direct impingement gas principle and features an in-line stock, aluminum alloy receiver, and reinforced fiberglass furniture. The AR-10 was built in relatively small numbers with perhaps 10,000 rifles assembled.

The differences between the AR-10 and other rifles of the time were stark, and its appearance was unique. When it was introduced in 1956, it was almost two pounds (1 kg) lighter than most infantry rifles. It was significantly easier to control in automatic fire, was more accurate in semi-auto fire, and arguably handled better than any other weapon of the period.

1 Design
2 History
3 Rebirth
4 External links
5 Books

[edit] Design

The AR-10's basic design is credited to Eugene Stoner at Armalite, then a division of the Fairchild Aircraft Corporation. The innovative features of the AR-10 would eventually be developed into the U.S. Army's M16 rifle. While mostly original, the AR-10 built upon previously proven designs. From the FAL it took the hinged receiver system allowing the rifle to be opened for cleaning much like a break-action shotgun. The bolt locking mechanism is similar to the Johnson M1941 Rifle (itself an adaptation of the Browning designed Remington model 8 bolt). From the German FG42 and Johnson Light Machinegun came the idea of straight-line stocks to reduce muzzle climb in fully-automatic fire. Fairchild was an aircraft manufacturer, and the use of plastics, titanium, and aluminum were common in the aircraft industry at the time, though not generally used in firearms.

The gas system, bolt carrier, and bolt-locking design was novel for its day. Most gas-operated rifles divert combustion gas from a port in the barrel to a piston and cylinder arrangement adjacent to the port. In Stoner's design the gas travels from a port near the middle of the barrel through a steel tube back into the receiver. The gas enters a chamber formed between the rear of the bolt and the inside of the bolt carrier, which has a built-in gas cutoff. This use of the bolt and bolt carrier for the separate actions of a piston and gas cylinder simplified construction and saved weight. Movement of the bolt carrier was in-line with the bore, greatly improving inherent accuracy, as well as keeping the rifle on target as the gun fired. Since the straight-line stock placed the shooter's eye well above the barrel the rifle's sights were mounted high, with the rear sight contained in a carrying handle that also protected the cocking/charging lever.

The receiver was made from forged and machined aluminum to reduce weight. The bolt locked into an extension on the barrel instead of the receiver allowing for a lightweight receiver while not reducing the strength of the bolt locking mechanism. On a few prototype guns, a all-aluminum ('Sullaloy') or aluminum/steel barrel was fitted at the insistence of George Sullivan, Armalite's president, though all production AR-10s utilized a solid steel barrel. The stock was made from a plastic-reinforced fiberglass with a core of rigid plastic foam. The handguards and pistol grip were also fiberglass. The AR-10's method of rotary bolt locking, straight-line recoil, and gas operation enhanced its inherent accuracy. At the time, the AR-10 was the most accurate standard-issue selective-fire military rifle ever built.

[edit] History

ArmaLite first opened as a division of Fairchild in 1954, specifically to bring new materials and designs to the firearm industry. Later that year they were joined by Eugene Stoner, a talented small arms engineer. Armalite quickly released a number of interesting rifle designs.

At the time the Army was in the midst of testing several rifles to replace the obsolescent 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 Fabrique Nationale submitted their FN FAL as the T48. Armalite's AR-10 entered the competition late, submitting two AR-10 rifles in the fall of 1956 to the United States Army's Springfield Armory for testing. Initial comments by Springfield Armory test staff were favorable, and some testers commented that the AR-10 was the best lightweight automatic rifle ever tested by the Armory.

Unfortunately for Armalite, the rifle's aluminum/steel composite barrel (an untried prototype design specified for the tests by George Sullivan over Stoner's vehement objections) burst in a torture test conducted by Springfield Armory. Armalite quickly replaced it with a conventional steel barrel, but the damage had been done. The final Springfield Armory report advised against adoption of the rifle. Though Army politics are credited with rejection of both the AR-10 and T48 (FN FAL), it was nevertheless true that the AR-10, a brand-new design, was at a disadvantage compared to competing rifle designs with longer development cycles. In the end the Army chose the conventional T44, which entered production as the M14 rifle in 1957.

In 1957, Fairchild Armalite sold a manufacturing license for the AR-10 to a Netherlands (Holland) arms manufacturer named Artillerie Inrichtingen (AI). Firearms historians have separated AR-10 production into at least four basic identifiable versions, along with various sporting, carbine and other experimental designs and calibers. The four main variants have been termed the Hollywood model (Armalite prototypes and initial production), the Sudanese model, the Transitional, and the Portuguese model AR-10. AI built the vast majority of these rifles, beginning with the Sudanese model AR-10. The Sudanese version was equipped with a lightweight, fluted steel barrel and adjustable gas regulator, and weighed only 7.25 lbs. empty. Over time, AI would engineer additional improvements to the AR-10, including the provision of a heavier barrel with chrome-lined chamber, a different cocking mechanism and simplified gas regulator, and a forward-assist device for the bolt carrier.

AR-10 production was limited, though Guatemala, Burma, Italy, Cuba, Sudan and Portugal all purchased AR-10 rifles for limited issue to their military forces. Sudanese-variant AR-10s were employed in frequent clashes with guerrilla forces and conflicts with neighboring countries, and captured rifles eventually turned up in unofficial service with various African armies and guerrilla forces, even the French Foreign Legion. The AR-10 remained in service with Sudanese Special Forces until 1985. In 1958, a special 7.62x39 mm caliber variant of the Sudanese AR-10 was produced in very small numbers for evaluation by Finland and Germany. The Italian navy acquired the AR-10 for its COMSUBIN underwater commando teams. Germany, Austria, Holland, Finland, and South Africa also purchased small numbers of the AR-10 for test purposes, and Cuba's Batista government purchased 100 rifles in 1958. Fidel Castro's forces eventually captured the AR-10 shipment intact. In 1959, Fidel, his brother Raul, and Che Guevara test-fired the AR-10 outside Havana, and were reportedly impressed by the weapon's firepower. Castro later apparently gave some of the AR-10 rifles to Communist revolutionaries in the Dominican Republic, where captured rifles from the Cuban shipment were found on the bodies of guerrillas killed in firefights with government forces.

The final AI design is known as the 'Portuguese' model AR-10. Most of them were sold to the Portuguese Air Force by the Brussels-based arms dealer SIDEM International in 1960. These rifles in particular saw considerable combat service in counterinsurgency warfare in Africa with Portuguese paratroop (paraquedista) battalions and other elite forces in Angola and Mozambique. In Portuguese service the AR-10 soon gained a reputation for accuracy (some rifles would group into 1" at 100 meters with service ammunition) and reliability despite rugged African service conditions.

Some Portuguese-model AR-10s were fitted with AI-modified upper receivers in order to mount 3x or 3.6x telescopic sights. These rifles were used by marksmen on small patrols to eliminate individual enemy at extended ranges in open country. Other AR-10s were used by the paratroopers in a secondary role to launch rifle grenades. The Armalite's built-in gas cutoff design enabled the rifle to fire mounted grenades without adjustment of the gas system, and the self-loading action would even eject the spent blank shells and load the next one, allowing several grenades to be quickly launched. Such constant pounding took its toll on rifle stocks, and some Portuguese rifles were fitted with all-metal buttstocks to withstand the added recoil and strain caused by frequent grenade-firing. Plans to augment issue of the AR-10 rifle were stymied after Holland embargoed further shipments of the rifle to Portugal, and most airborne units were subsequently issued a collapsible stock version of the German G3 rifle. Nevertheless, the AR-10 continued in service with a few paratroop units, and was in use as late as 1975 in the Portuguese Timor (East Timor) emergency.

In 1958, Armalite developed the 5.56 mm AR-15 from the AR-10. The company continued its efforts to sell both the AR-10 and AR-15 to various military forces around the world. However, the AR-10 model marketed by Armalite after 1958 was not the product-improved AR-10 developed by Artillerie Inrichtingen, but was instead a design scaled-up from AR-15 plans and specifications, known as the AR-10a. All of the product improvements incorporated by AI were lost in the new AR-10a. While interest in the AR-15 design was considerable, the AR-10a failed to attract much interest from domestic or foreign military customers. In 1959, Armalite sold its rights to the AR-10/AR-15 to Colt, who successfully marketed the AR-15 to the U.S. military. Disappointed with Armalite's marketing efforts, Fairchild dissolved its association with Armalite in 1962.

By 1960, Artillerie Inrichtingen had ceased all licensed production of the AR-10. By that time, less than 10,000 AR-10's had been produced, mostly military select-fire rifles, with a few semi-automatic-only rifles produced for civilian use.

With the rights to the AR-15 design sold and AR-10 production discontinued, Armalite next developed a series of new rifle designs in 5.56 mm and 7.62 mm. These rifles utilized more traditional gas piston designs along with stamped and welded steel construction in place of aluminum forgings. The 7.62 mm AR-16 (not to be confused with the M16) was produced only in prototype quantities. The AR-18 was produced in limited quantites by Armalite and other manufacturers, and its basic operating mechanism was later adapted and used in several later assault rifle designs. By the 1970s, Armalite had essentially stopped all new rifle development, and the company became moribund.

In later years, some ex-military Sudanese and Portuguese AR-10s were sold to civilian markets in the U.S., Canada, Australia, and New Zealand. Nearly all of the rifles imported to the latter three countries had their full-automatic fire selector disabled. As many as 2500 Australian AR-10 rifles may have been seized and destroyed as a result of anti-gun legislation in 1997.

Most of the AR-10 ex-military rifles shipped to the USA were in the form of parts kits, having been previously dismantled, though a few were legally imported as Class III weapons. Large numbers of AR-10 7.62mm magazines were imported as well. Many of these 'kit' rifles were combined with various semi-auto receivers made by civilian manufacturers in order to permit legal ownership.

[edit] Rebirth

In 1995, former Army Ordnance officer Mark Westrom, owner of Eagle Arms, purchased the ArmaLite brand and the company became Armalite Inc. Shortly thereafter Armalite introduced a modern version of the AR-10. The new Armalite AR-10 was patterned after the AR-15A2, scaled up to take the 7.62 x 51 mm NATO cartridge, along with various design improvements designed to strengthen the rifle. Ironically the original AR-15 itself was a scaled-down AR-10. The new AR-10 is offered in several versions including a carbine and target model, and one version is chambered in 300 Rem SAUM. Some rifles have been acquired by U.S. military special operations and other forces for testing and evaluation.