Receiver (firearms) in the context of "Single-shot"

The Lee–Enfield (Enfield rifle) is a bolt-action, magazine-fed repeating rifle that served as the main firearm of the military forces of the British Empire and Commonwealth during the first half of the 20th century, and was the standard service rifle of the British Armed Forces from its official adoption in 1895 until 1957.

A redesign of the Lee–Metford (adopted by the British Army in 1888), the Lee–Enfield superseded it and the earlier Martini–Henry and Martini–Enfield rifles. It featured a ten-round box magazine which was loaded with the .303 British cartridge manually from the top, either one round at a time or by means of five-round chargers. The Lee–Enfield was the standard-issue weapon to rifle companies of the British Army, colonial armies (such as India and parts of Africa), and other Commonwealth nations in both the First and Second World Wars (such as Australia, New Zealand, South Africa, and Canada). Although officially replaced in the United Kingdom with the L1A1 SLR in 1957, it remained in widespread British service until the early/mid-1960s and the 7.62 mm L42A1 sniper variant remained in service until the 1990s. As a standard-issue infantry rifle, it is still found in service in the armed forces of some Commonwealth nations, notably with the Bangladesh Police, which makes it the second longest-serving military bolt-action rifle still in official service, after the Mosin–Nagant (Mosin-Nagant receivers are used in the Finnish 7.62 Tkiv 85). Total production of all Lee–Enfields is estimated at over 17 million rifles.

An AR-15–style rifle is a lightweight semi-automatic rifle based on or similar to the Colt AR-15 design. The Colt model removed the selective fire feature of its predecessor, the original ArmaLite AR-15, which is a scaled-down derivative of the AR-10 design (by Eugene Stoner). It is closely related to the military M16 rifle.

ArmaLite sold the patent and trademarks for both to Colt's Manufacturing Company in 1959 after the military rejected the design in favor of the M14. After most of the patents for the Colt AR-15 expired in 1977, many firearm manufacturers began to produce copies of the rifle under various names. While the patents are expired, Colt has retained the trademark to the AR-15 name and is the sole manufacturer able to label their firearms as such.

The lock of a firearm is the mechanism used to initiate firing. It is generally used as a historical term, referring to such mechanisms used in muzzle-loading and early breech-loading firearms, as modern firearms uniformly fire by use of a firing pin to strike the rear of a cartridge. Side-lock refers to the type of construction, in which the individual components of the mechanism are mounted either side of a single plate. The assembly is then mounted to the stock on the side of the firearm. In modern firearm designs, the mechanism to initiate firing is generally constructed within the frame or receiver of the firearm and is referred to as the firing or trigger mechanism.

The ArmaLite AR-15 is a gas-operated assault rifle manufactured in the United States between 1959 and 1964. Designed by American gun manufacturer ArmaLite in 1956, it was based on its AR-10 rifle. The ArmaLite AR-15 was designed to be a lightweight rifle and to fire a new high-velocity, lightweight, small-caliber cartridge to allow infantrymen to carry more ammunition.

In 1959, ArmaLite sold its rights to the AR-15 to Colt due to financial difficulties and limitations in terms of manpower and production capacity. After modifications (most notably, the charging handle was re-located from under the carrying handle like AR-10 to the rear of the receiver), Colt rebranded it the Colt 601, however, it still carried the Armalite markings due to contractual obligations to Armalite/Fairchild Aircraft Co. Colt marketed the redesigned rifle to various military services around the world and was eventually adopted by the U.S. military in January 1962 and subsequently designated as M16 rifle in December 1963, which went into production and service in 1964.

In firearms, the forearm (also known as the fore-end/forend, handguard or forestock) is a section of a gunstock between the receiver and the muzzle. It is used as a gripping surface to hold the gun steady and is usually made out of heat-insulating material such as wood or reinforced plastic. Near the front of the forearm there is often an underside sling swivel stud and sometimes also a barrel-band to secure the forearm to the barrel (as seen in the photo).

Some forearms are equipped with additional heat shields to protect the user from heat radiating from the barrel when the firearm is fired.