M21 (rifle) – Wikipedia

M21
general information
Military name:	M21
Developer/manufacturer:	Army Weapons Command, Combat Development Command Limited Warfare Agency
Development year:	1969
Production time:	Since 1969
Model variants:	XM21, XM25/M25
Weapon category:	Sniper rifle
Furnishing
Overall length:	1118 mm
Weight: (Ungeladen)	3,950 kg
Running length:	560 mm
Technical specifications
Caliber:	7,62 × 51 mm NATO
Possible magazine fillings:	10 or 20 cartridges
Number of trains:	4
Twist:	To the right
Visor:	Rifesty tube, 3 to 9 times
Closure:	Rotary cap
Ladeprinzip:	Gas pressure loader
Lists on the subject

The M21 Is a self-charging and charging rifle in the caliber 7.62 mm NATO.

Before the beginning of the Vietnam War, the US Army used the M1D, which came from the Second World War, the M1D, which was equipped with the M84 target scope. In the introduction of the M14, no successor for the M1D had initially been planned – the sniper training was only of low status at the US Army.
However, the fights in Vietnam soon showed that there was an urgent need for suitable rifles. In 1966 the M14 rifle is therefore tested with the 2.2-fold enlarged M84 targets. The final report came to the conclusion that:

-The standard cartridge for the use of sniper inserts is not suitable,

– the rifle scope M84 is not sufficient,

-The M14 is sufficiently accurate for use according to the national match specification with fiber optic-reinforced shaft and the Matchparton M118.

The US Army Marksmanship Training Unit (USAMTU – a unit that trains competition shooters and also has its own workshops and gunsmith) revised the M14 National Match even further; Instead of the M84 target remote tube, a new rifle scope was tested, the functional principle of which the army lieutenant James Leatherwood had patented. The new rifle scope was based on the commercial Redfield 3-9-fold “Accurange”. In addition to a crosshairs, the forego had two horizontal and vertical bars. The horizontal beams served for the distance setting – the shooter took up his goal and adjusted the zoom of the rifle scope until the bars with top head and belt line of the target met. A tax curve postponed the foregoing in such a way that it was adapted to the measured distance. It was referred to as “Art” (Adjustable Ranging Telescope).

The rifle has now been referred to as the M14 “Usamtu Accurized National Match”; In the summer of 1969, the rifle target scope combination was temporarily introduced as the “XM21 Sniper Weapon System”. In 1972 the “X” fell away.

In 1988, the M21 was officially replaced by the M24 SWS as a sniper rifle in the US Army.

The M21 is a gas pressure loader with a rotary cap. The cartridges are borne via a pole magazine. It is largely identical to the M14, but has an artificial arcamed shaft and fiber optic bed for the system. Deduction, muzzle fire damper, gas system and locking spring were revised so that they do not negatively affect the precision. The fire selection device is constantly blocked.

Despite the replacement as a sniper rifle, the weapon is still a so -called designated Marksman Rifle in the service of the armed forces. It is used where the range of the assault rifle is too low, and thus serves as a support weapon in the group (the smallest infantry unit). For this purpose, further changes such as the retrofitting of a Picatinny rail were made for the assembly of various riflescopes. A result of these modifications is the M25-an improved M21-that was developed in 1980 for the special units of the US forces.

Commons : M21 – Album with pictures, videos and audio files

• R. Blake Stevens: Modern U.S. Military Small Arms Series – Volume One / U.S. Rifle M14 – from John Garand to the M21. Collector Grade Publications, Cobourg/Ontario, Kanada, 1991, ISBN 0-88935-110-4.