Basic parts of a AR rifle - Terminology

The following is a brief photo collection detailing the most basic components of a AR style rifle and a brief definition of what each part is and the basic function it serves.

The rifle that will be specifically featured is the Smith and Wesson M&P 15T, although the information presented generally applies to all AR style rifles (Olympic Arms, Stag Arms, DPMS, etc). Click on any of the photos to enlarge them.

There are a few common parts of a rifle you will find on virtually all AR rifle models and variations. This particular AR rifle is a Smith and Wesson M&P 15T. This model uses .223 or 5.56 ammunition. The AR rifle series is extremely popular and has found favor in United States law enforcement departments and the United States military divisions.


The next photo lists the basic AR components and their locations on the left side of the rifle.


Starting from the upper left, the FLASH SUPPRESSOR reduces the amount of flash exiting the barrel of the rifle when the weapon is fired. The FOLDING FRONT SIGHT is a integrated sight for the rifle and is used to align the rifle on a target in conjunction with the rear sight. The MODULAR RAIL FOREND (MRF) is a rail system designed to mount and secure accessories and extra equipment for the rifle.

The MAGAZINE holds the ammunition for the rifle and can be removed for reloading. The LOWER RECEIVER is the lower part of the main frame of the rifle (it houses the trigger mechanism among other items). The BOLT CATCH is used to lock the charging handle in an open position, or to release it from an open position.

The TRIGGER discharges the weapon. The FOLDING REAR SIGHT is a integrated sight for the rifle and is used to align the rifle on a target in conjunction with the front sight. The SAFETY SELECTOR LEVER places the rifle in either a SAFE or FIRE mode of operation.

The CHARGING HANDLE is used to manually chamber a cartridge (initially load the rifle). The STOCK is used to brace the firearm securely against the shoulder of the person utilizing the rifle.

The next photo lists the basic AR components and their locations on the right side of the rifle.


Starting from the left, the STOCK is used to brace the firearm securely against the shoulder of the person utilizing the rifle. The CHARGING HANDLE is used to manually chamber a cartridge (initially load the rifle). The MAGAZINE RELEASE allows the magazine to be removed or pulled out from the rifle.

The FOLDING REAR SIGHT is a integrated sight for the rifle and is used to align the rifle on a target in conjunction with the front sight. The UPPER RECEIVER is the upper part of the main frame of the rifle (it contains the barrel and sights among other items). The DUST COVER keeps debris and foreign items out of the barrel and bolt of the rifle. (NOTE: The DUST COVER will automatically open whenever the CHARGING HANDLE is pulled back).

The MAGAZINE holds the ammunition for the rifle and can be removed for reloading. The FOLDING FRONT SIGHT is a integrated sight for the rifle and is used to align the rifle on a target in conjunction with the rear sight. The FLASH SUPPRESSOR reduces the amount of flash exiting the barrel of the rifle when the weapon is fired.

Although there are many different makes and models of AR rifles, most have the same parts and are located in the same positions. (SPECIAL NOTE: STAG ARMS makes custom AR style rifles for people who are left-handed. In their specially designed AR style rifles, the "usual" left and right sides of an AR rifle have been reversed for much easier left-handed use)

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