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M21 Sniper Weapon System

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Title: M21 Sniper Weapon System  
Author: World Heritage Encyclopedia
Language: English
Subject: M25 Sniper Weapon System, List of crew-served weapons of the U.S. Armed Forces, M21, Carlos Hathcock, Springfield Armory M1A
Collection: 7.62 Mm Firearms, Rifles of the United States, Semi-Automatic Rifles, Sniper Rifles
Publisher: World Heritage Encyclopedia

M21 Sniper Weapon System

Rifle, 7.62 mm, Sniper, M21
M21 sniper rifle
Type Designated marksman rifle
Place of origin United States
Service history
In service 1969–Present
Used by See Users
Wars Vietnam War, Iraq War (Limited use)
Production history
Designer Marines Weapons Command,
Combat Development Command,
Limited Warfare Agency
Designed 1969
Manufacturer Rock Island Arsenal, Springfield Armory
Variants M25
Weight 5.27 kg (11.6 lb)
Length 1118 mm (44 in)
Barrel length 560 mm (22 in)

Cartridge 7.62×51mm NATO
Action Gas-operated, rotating bolt
Muzzle velocity 853 m/s (2,800 ft/s)
Effective firing range 822 m (900 yd)
Feed system 5, 10 or 20-round detachable box magazine
Sights Front: National Match front blade .062
Rear: Match-grade hooded aperture with one-half minute adjustments for both windage and elevation.
26¾ in sight radius.

The M21 Sniper Weapon System (SWS) is the semi-automatic sniper rifle adaptation of the M14 rifle. It is chambered for the 7.62×51mm NATO cartridge.


  • Overview 1
  • M25 Sniper Weapon System 2
    • Technical specifications 2.1
  • Service 3
    • Commercial 3.1
  • Users 4
  • References 5
  • External links 6


Vietnam War era sniper rifles, US Army XM21 (top) and USMC M40 (bottom)

The United States Army wanted an accurate sniper rifle during the Vietnam War. The M14 was selected because of its accuracy, reliability, and the ability for a quick follow up shot. As a result, in 1969, the Rock Island Arsenal converted 1,435 National Match (target grade) M14s by adding a Leatherwood 3–9× Adjustable Ranging Telescope and providing National Match grade ammunition.

This version, called the XM21, had a specially selected walnut stock and was first fielded in the second half of 1969. An improved version with a fiberglass stock was designated the M21 in 1975. The M21 remained the Army's primary sniper rifle until 1988, when it was replaced by the M24 Sniper Weapon System; some M21s were later re-issued and used in the Iraq War.[1][2]

In standard military use, the M21 uses a 20 round box magazine as the other members of the M14 family and weighs 11 pounds (5.27 kg) without the scope. The U.S. military never officially authorized or purchased magazines in any other capacity, although 5- and 10-round magazines are available.

M25 Sniper Weapon System

The M25 is an upgraded version of the M21 developed by 10th Special Forces Group's armorers for use by United States Army Special Forces and United States Navy SEALs in the late 1980s. It saw some use during Operation Desert Storm in January and February 1991.

Technical specifications

  • Action: A M14NM (National Match) action.
  • Stock: A McMillan M1A fiberglass stock
  • Optics: A Bausch & Lomb Tactical 10×40 scope, or sometimes Leupold MK4 10× scopes.
  • Bipod: A Harris bipod is often attached for stability during prone firing.


The XM21 Sniper Weapon System was used by the U.S. Army in the Vietnam War, and the M21 saw limited action in military conflicts and operations in the late 1960s until the late 1980s. It was used by the U.S. Army Rangers during the Invasion of Grenada in 1983. There are limited numbers in some Army National Guard units and in a few specialized active units such as the OPFOR units of the Joint Readiness Training Center. The XM21 served from 1969 to 1975, and the M21 officially served as the main Army sniper rifle from 1975 to 1988 until the introduction of the M24, which had supplanted the M21 in Ranger Battalions by 1990. Though many M-14 and M-21 variants came back to favor in the Iraq and Afghan wars in the 2000s.[2][3]


Springfield Armory, Inc. also manufactures variants of its M1A rifle called M21 Tactical Rifle and M25 White Feather Tactical/Carlos Hathcock rifle, which are based upon M21 and M25 Sniper Weapon Systems but are slightly different, most notably they are fitted with a Picatinny rail to mount a scope and a Krieger barrel.[4]



  1. ^
  2. ^ a b "U.S. Army M21 & XM21 Sniper Weapon System". Sniper Central. 
  3. ^ M21 Sniper Rifle -
  4. ^ Springfield Armory, Inc.'s official pages of the M21 Tactical Rifle and M25 White Feather Tactical/Carlos Hathcock model

External links

  • M21 Tactical
  • U.S. Army Field Manual 23–10, Appendix B: M21 Sniper Weapon System
  • Lee Emerson's Word doc. on the M14 and nearly all known variants
  • SniperCentral's page about the M21
  • Brief M21 description and history from the U.S. Army.
  • M21 on Global (the same text can be found at
  • M25 at
  • M25 at
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