Upper receivers are available with barrels of different weights, lengths, calibers, and rail systems with various sights and accessories. Thus one upper receiver can quickly and easily be substituted for another. The upper receiver incorporates the fore stock, the charging handle, the forward assist, the gas operating system, the barrel, the bolt and bolt carrier assembly. The AR-15A2's most distinctive ergonomic feature is the carrying handle and rear sight assembly on top of the receiver. This twisting action follows the groove cut into the carrier and forces the bolt to twist and 'lock' into the barrel extension. As the bolt's locking lugs move past the barrel extension, the cam pin twists into a pocket milled into the upper receiver. The round is guided by feed ramps into the chamber. The bolt's locking lugs push a fresh round from the magazine as the bolt moves forward. A groove machined into the upper receiver guides the bolt cam pin and prevents it and the bolt from rotating into a closed position. The buffer spring begins to push the bolt carrier and bolt back toward the chamber once it is compressed sufficiently. As soon as the neck of the case clears the barrel extension, the bolt's spring-loaded ejector forces it out the ejection port in the side of the upper receiver.Д«ehind the bolt carrier is a plastic or metal buffer, which rests in line with a return spring. The bolt's rearward motion extracts the empty cartridge case from the chamber. Once the bolt is fully unlocked it begins its rearward movement along with the bolt carrier. As the bolt carrier moves toward the butt of the gun, the bolt cam pin, riding in a slot on the bolt carrier, forces the bolt to rotate and thus unlocks it from the barrel extension. ДЄt this point, the bolt is locked into the barrel extension by locking lugs, so the expanding gas forces the bolt carrier backward a short distance. Here, the gas tube protrudes into a 'gas key' (bolt carrier key), which accepts the gas and funnels it into the bolt carrier. The gas expands into the port and down a gas tube, located above the barrel that runs from the front sight base into the AR-15's upper receiver. Gas is tapped from the barrel as the bullet moves past a gas port located above the rifle's front sight base. Designer Eugene Stoner did not consider the AR-15 to be a conventional direct impingement mechanism, but that is how it came to be characterized. This mechanism is often called ' direct gas impingement' (DGI), although it differs from prior gas systems.

The bolt carrier acts as a movable cylinder and the bolt itself acts as a stationary piston. Patent 2,951,424 describes the cycling mechanism used in the original AR-15. By May 2020, changed market conditions encouraged Colt to resume production for sales to private users. It would still produce the AR-15 for police and military units. On September 20, 2019, Colt announced that it would no longer produce the AR-15 for private use, due to market saturation. Colt and others continued to sell legally compliant versions during that period. Sale of new AR-15s in the USA was banned by the Federal Assault Weapons Ban from 1994 to 2004. Colt has since made many different models of AR-15 rifle and carbine models, including the AR-15, AR-15A2, AR-15A3, AR-15A4, and others. 223 Remington, with a 20-inch barrel, issued with 5-round magazines. The first mass production version was the Colt AR-15 Sporter, in. Colt started selling the semi-automatic version of the M16 rifle as the Colt AR-15 in 1964. This example is fitted with an early waffle-patterned 20-round magazine.Дue to financial problems, and limitations in terms of manpower and production capacity, ArmaLite sold the AR-15 design and the AR-15 trademark along with the ArmaLite AR-10 to Colt's Manufacturing Company in 1959.

Colt's Manufacturing Company currently owns the AR-15 trademark and is used exclusively for its line of semi-automatic AR-15 rifles.ДЄ Colt AR-15 on display at the National Firearms Museum. It is a semi-automatic version of the M16 rifle sold for the civilian and law enforcement markets in the United States. The Colt AR-15 is a lightweight, magazine-fed, gas-operated semi-automatic rifle.

Picatinny rails, which allows the use of various scopes and sighting devices.

Detachable carrying handle with adjustable rear iron sight assembly.

Fixed adjustable front and rear iron sights.Issued with 5-, 10-, 20- & 30-round STANAG magazines See List of Colt AR-15 & M16 rifle variants Complete AR-15A2 rifle set with manual, 5.56 mm ammunition and magazines

Colt ar 15 parts kits