M21 Sniper Weapon System
sniper rifle
The M21 Sniper Weapon System (SWS) in the US Army is a national match grade M14 rifle, selected for accuracy, and renamed the M21 rifle. The M21 uses a commercially procured 3–9× variable power telescopic sight, modified for use with the sniper rifle. It is chambered for the 7.62×51mm NATO cartridge.
Overview
The use of "sharpshooters" (or snipers) can be traced in U.S. military history from the time of the Revolutionary War of 1775–1781. Every U.S. military action since that time has required the special talent of such men. From 1955 to 1956, the United States Army Marksmanship Training Unit undertook a program to "reiterate the lessons learned" from past wars. However, this program was short-lived. The prevailing military attitude then envisioned any future conflict as nuclear with defeat or victory decided in hours.
With the adoption of the M14 service rifle, no provision was made for an M14 sniper rifle, [and] the designation of a sniper in the rifle squad was discontinued. The conflict in Vietnam revived the need for snipers.
Begin with the source’s own compact description: “M21 Sniper Weapon System” is sniper rifle. The dossier treats that line as a proposition to test through Sniper, Weapon and System, not as a finished interpretation.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Aug 10, 2026. The linked authority identifier is Q1196923. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1775, 1781, 1955 and 1956.
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This entry incorporates text from “M21 Sniper Weapon System” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.