Sunday, April 27, 2008

m21

Caliber: 7.62x51 NATO (.308 Winchester)
Mechanism: Rotating bolt, gas operated semi-automatic rifle.
Length: 1118 mm
Barrel: 559 mm
Weight: without scope 5.27kg
Capacity: 20 round box magazine

The XM21 sniper rifle was developed jointly by the Army Weapons Command at Rock Island, Combat Development Command at Ft. Benning, and the Limited Warfare Agency at Aberdeen, during late 1960s. The XM21 was an accurized M14 National Match (NM) semi-automatic rifle equipped with a Leatherwood 3X-9X Adjustable Ranging Telescope (ART). The Rock Island Arsenal converted 1,435 M14NM rifles to XM21 sniper rifles for initial fielding to Vietnam in 1969. The rifle was initially fielded with a wooden stock, which was later replaced with a fiberglass stock. The XM21 was officially type classified M21 in 1975, and remained a standard US Army sniper rifle until 1988, when it was officially replaced with M24 SWS. The M21 was accurate to 750 yards (690m). The rifle used 7,62mm NATO M118 ammunition, especially developed for sniping and long range match shooting. The ART telescope featured a variable magnification power of from 3X to 9X, for adjustable ranging between 300m and 900m. This adjustable ranging feature removed much of the guesswork from aiming at the target. The ART was ballisticly matched with M118 ammunition.
Later on, a modified M25 sniper rifle was developed for US Scecial Operations forces. It retained basic M14 / M21 mechanisms but added a McMillan polymer stock, some commercially available parts (such as replacement gas piston), and a new scope mount. M25 rifles are ususally issued with more modern Baush & Lomb or Leupold telescope sights. Older Sionics suppressor is replaced by Ops Inc suppressor.
Finally it must be noted that more than few M21 rifles were recently re-issued to US forces in Iraq and Afghanistan to complement older M24 rifles before enough M110 semi-automatic rifles will be available. Some old M14 rifles also were recently converted to M21 configuration as well. Most such conversion and re-issues use new generation scope mounts with Picatinny rails and new-generation telescope sights.

M21 sniper rifle is gas operated, semi-automatic rifle which uses Garand-type rotary bolt locking and gas-operated short stroke piston system, located below the barrel. M21 rifle retained adjustable iron sights of M14 rifle, and added a telescope or night sight using standard M14 rifle side mount (each military M14 rifle was manufactured with provisions for mounting a scope bracket on the left side of the receiver). For special operations, M21 rifle was often issued along with Sionics sound suppressor (silencer).

McMillan TAC-50 long range sniper rifle (USA)


Caliber: .50BMG (12.7x99mm)
Operation: manually operated rotary bolt action
Barrel: 736 mm
Weight: 11.8 kg
Length: 1448 mm
Feed Mechanism: 5-round detachable box magazine

TAC-50 sniper rifle is produced in USA by McMillan Bros. Rifles Co. This long range anti-materiel / anti-personnel weapon is based on previous designs from the same company, which first appeared during late 1980s. McMillan Co makes several versions of .50 caliber rifles, based on same proprietary action, for military, law enforcement and civilian use. TAC-50 is a military / LE weapon, which is standard Long Range Sniper rifle of Canadian Armed Forces since 2000. Rifles of TAC-50 family is capable of outstanding accuracy and guaranteed to provide 0.5 MOA groups with match grade ammunition. TAC-50 rifle is also credited with longest range documented kill on enemy soldier: in 2003, a Canadian sniper shot and killed an Afghani taliban insurgent from the range of 2430 meters (nearly one and a half mile).

McMillan TAC-50 is manually operated, rotary bolt rifle. Huge, full-size bolt has dual front locking lugs, and its body has spiral flutes to reduce weight. Heavy match-grade barrel is also fluted, and fitted with effective muzzle brake. Rifle is fed from detachable box magazines, holding 5 rounds each. Stock is made from fiberglass by McMillan Stocks, and is designed to be used from bipod only. Buttstock is adjustable for length of pull with rubber spacers, and can be folded to the side or removed for compact storage. Rifle has no open sights and can be used with a variety of telescopic or night sights; in Canadian service, standard sight is 16X telescope.

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Thursday, January 17, 2008

M82A1 or Light Fifty


Caliber: .50 BMG (12.7 x 99mm)
Operation: Short Recoil, Semi-Automatic
Overall Length: 1448 mm
Barrel Length: 737 mm
Feed Device: 10 Round Detachable Box Magazine
Sights: 10X Telescopic
Weight: 12.9 kg empty
Muzzle Velocity: 854 m/s (M33 Ball)
Max Effective Range: 1800 meters
Expected accuracy: 1.5 - 2.0 MOA or better

The Barrett Firearms company was founded by the Ronnie Barrett for a single purpose of building semi-automatic rifles chambered for powerful .50BMG ammunition, originally developed for and used in Browning M2HB heavy machine guns. Barrett began his work in early 1980s and first working rifles were available in 1982, hence the designation M82. Barrett continued to develop his rifle through 1980s, and developed improved M82A1 rifle by 1986. The first real success was the purchase of about 100 M82A1 rifles by the Sweden Army in 1989. Major success followed in 1990 - 1991, when US Military purchased numbers of the M82A1 during the operations Desert Shield and Desert Storm in Kuwait and Iraq. About 125 rifles were initially bought by US Marine Corps, orders from US Army and Air Force followed soon. The M82A1 is known for US Military as the SASR - "Special Applications Scoped Rifle", and it was and still is used as an anti-materiel weapon and EOD (explosive ordnance disposal) tool. The long effective range along with high energy and availability of highly effective ammunition such as API and Raufoss M213 allows for effective operations against targets like radar cabins, trucks, parked aircrafts and so on. M82 also can be used to defeat enemy snipers or criminals from standoff range or when targets are behind the cover, but the anti-personnel work is not a major application for Barrett M82 (or any other .50BMG rifle, for that matter).

Further development led to the M82A2 bull-pup rifle (1987), which was designed to be fired from the shoulder, but did not succeed, and was soon dropped from production. The M82A2 was obviously designed as a cheap anti-helicopter weapon, suitable for use against highly mobile targets when fired from the shoulder. The latest derivative of the M82 family is the M82A1M rifle, adopted by USMC as the M82A3 SASR and bought in significant numbers. This rifle differs from M82A1 in that it have a full length Picatinny rail that allows a huge variety of scopes and sighting devices to be mounted on the rifle. Other changes are addition of the rear monopod, slightly lightened mechanism and detachable bipod and muzzle brake. The Barrett M82 rifles were bought by various military and police countries from at least 30 countries, such as Belgium, Denmark, Finland, France, Greece, Italy, Mexico, Portugal, Saudi Arabia, Spain, Sweden, Turkey, UK, USA and others. The M82 also is widely used for civilian .50 caliber long range shooting competitions, being fired accurately out to 1000 yards (911 meters) and even further.

As a side note I must point out that the Barrett M82A1 rifle was recently (2002) used as a platform for experimental OSW (Objective Sniper Weapon) prototype. The M82A1 rifle was fitted with shorter barrel of 25mm caliber, and fired low-velocity high explosive shells developed for 25mm OCSW automatic grenade launcher. The experimental OSW showed an increased effectiveness against various targets but the recoil was beyond the human limitations.

The M82 is a recoil operated, short barrel stroke, semi-automatic firearm. When gun is fired, barrel initially recoils for a short distance (about an inch - 25 mm) being securely locked by the rotating bolt. After the short travel a post on the bolt, engaged in the curved cam track in the receiver, turns bolt to unlock it from the barrel. As soon as the bolt unlocks, the accelerator arm strikes it back, transferring some part of the recoil energy of the barrel to the bolt to achieve the reliable cycling. Then barrel is stopped and the bolt continues back, to extract and eject a spent case. On its return stroke bolt strips the fresh cartridge from the box magazine and feeds it into the chamber and finally locks itself to the barrel. The striker also is cocked on the return stroke of the bolt. The gun is fed from the large detachable box magazines, that hold 10 rounds.

The receiver is made from two parts (upper and lower), stamped from sheet steel and connected by cross-pins. Heavy barrel is fluted to improve heat dissipation and save weight, and fitted with large and effective reactive muzzle brake. On the earlier models the muzzle brakes were of round cross-section, latter M82 rifles are equipped with two chamber brakes of rectangular cross-section. M82A1 rifles are fitted with scope mount and a folding backup iron sights. M82 rifles are often equipped with Leupold M series 10X telescope sights. The M82A1M (USMC M82A3) rifles have long Picatinny accessory rail mounted on the top of the receiver, that can accept wide variety of scopes, day or night. Every M82 rifle is equipped with folding carrying handle and with a folding bipod (both are detachable on M82A3). M82A3 also fitted with the detachable rear monopod under the butt. The buttpad is fitted with soft recoil pad to further decrease the felt recoil. M82A1 and M82A3 rifles could be mounted on the M3 or M122 infantry tripods (originally intended for machine guns) or on vehicles using special Barrett soft-mount. M82A1 can be fitted with carry sling but according to those who carried it in the field, M82 is way too uncomfortable to be carried on sling due to excessive length and heavy weight. It is usually carried in special carry soft or hard case.

The M82A2 differed from M82A1 mostly in that the pistol grip along with trigger had been placed ahead of the magazine, and the buttpad has been placed below the receiver, just after the magazine. Additional forward grip was added below the receiver, and the scope mount has been moved forward too.