M40 rifle

Infobox Weapon
name= M40


caption= The M40A3
origin=flagcountry|United States
type= Sniper rifle
is_ranged=yes
service=1966 - present
used_by=flagcountry|United States
wars=
designer=
design_date=
manufacturer=
production_date=
number=
variants=
weight= M40A1: 6.57 kg (14.48 lb)
M40A3: 7.5 kg (16.5 lb)
length= M40A1: 1,117 mm (43.97 in)
M40A3: 1,124 mm (44.25 in)
part_length= 610 mm (24 in) (1:12 right hand twist)
M40A1: "Hart" (5 lands and grooves)
M40A3: "Schneider" Match Grade SS #73 (6 lands and grooves)
crew=
cartridge= 7.62 × 51 mm NATO
action= Bolt-action
rate=
velocity= 2550 fps (777 m/s) (w/175 gr. M118LR)
range= 1000 m (1094 yd)
feed= 5-round detachable box magazine
sights= Unertl 10x telescopic sight with Mil-Dots and BDC (specially designed for USMC)

The M40 is a bolt-action sniper rifle used by the United States Marine Corps. It has had three variants — the M40, the M40A1 and the M40A3. The M40 was introduced in 1966. The changeover to the A1 model was completed in the 1970s, and the A3 in the 2000s.

Each firearm begins life as a Remington 700, and is then extensively modified by hand by USMC 2112/gunsmiths at Marine Corps Base Quantico, using components from a number of suppliers. New M40A3s are being built, and A1s are upgraded to A3s as they rotate into the armory for service and repair. The rifles have had many sub-variations in telescopic sights, and smaller user modifications.

The original M40 was a military type-classified version of the Remington 700; it was factory-made, and had a one-piece wooden stock. The M40A1 and A3 switched to fiberglass, with new scopes added as well. The trigger pull on both models (M40A1/A3) is 3 to 5 lbs.

History

During the Vietnam War, the Marine Corps decided they needed a standard sniper rifle. After testing several possibilities, they ordered 700 Remington Model 40x rifles (target/varmint version of the Model 700 bolt-action rifle), and gave them the M40 designation. Most had a Redfield 3–9 power Accurange variable scope mounted. With time, certain weaknesses, primarily warping of the all-wood stock, became apparent. Sometime in the early 1970s, the USMC armorers at MCB Quantico began rebuilding the original M40s into M40A1s. The process involved, among other improvements, replacing the original wood stocks with McMillan A1 fiberglass stocks, as well as replacing the original Redfield scopes with Unertl scopes. The M40 was originally designed by Jack Cutty and Neill Goddard. The U.S. Army also uses the Remington 700/40x action as the basis for its M24 Sniper Weapon System. The primary difference between the Army and the USMC rifles is that while the USMC M40/A1/A3 utilizes the short action version of the Remington 700/40x (designed for shorter cartridges, such as .308 Winchester/7.62mm NATO, 7 mm/08 Remington, .243 Winchester), the Army M24 uses the long action version of the same rifle. The Long actioned M24 can use the .308 Winchester (7.62x51 NATO)but is mainly designed for full-length cartridges, such as the .30-06 Springfield, and Magnum cartridges, such as the 7 mm Remington Magnum, .300 Winchester Magnum and .338 Lapua). The U.S. Army reasoning behind this decision was to allow them to reconfigure the rifle in the larger, longer-range calibers if necessary. The M24's most popular cartridges are the .308 and .338 Lapua.

M40A3

Development of the M40A3 began in 1996, and the final product was revealed in 2001. Since then, numerous minor changes have occurred to the platform. It is highly possible that more changes will occur to the platform as it gains operational use in Iraq and Afghanistan. Listed here is the latest configuration known to be used in an M40A3.

Action — The M40 has always been based on the proven Remington 700 Short Action and this is no different in the M40A3. These actions are all chambered in 7.62 mm NATO and are house tuned by Marine armorers; the trigger guard assembly is manufactured by the DD Ross Company, though several M40A3s use Badger Ordnance trigger guards. In 2007, the Marine Corps began replacing the DD Ross trigger guard assemblies with the M5 detachable magazine trigger guard manufactured by Badger Ordnance.

Barrel — The barrel is a Schneider 610 /24-inch, 5-groove, 1:12" match-grade heavy barrel.

Stock — All service M40A3s are based upon the A4 Tactical Riflestock, a high-quality benchrest-style fiberglass riflestock made by McMillan Fiberglass Stocks and cast molded in an OD Green color. The action is glass bedded into the stock with aluminum pillars, while the barrel is allowed to "float" (it is attached only to the action), ensuring maximum accuracy. The stock has adjustable length-of-pull (through a buttstock spacer system) and a Marine manufactured adjustable saddle-type cheekpiece. The stock also has 5 mount flush cups, 2 on each side front and back and 1 on the rear underside. One bipod stud is located on the underside of the forearm.

Sling — The Model 1907 sling that has been historically used on M40A3s has been replaced with the Quick Cuff Model Two sling manufactured by Tactical Intervention Specialists.

Bipod — The M40A3s use a 6-9" Harris notched swivel type bipod with a KMW podlock. The QD bipod attaching screw is replaced with a screw made by Jon Tank of Tanks Rifle Shop.

Dayscope — A modified Schmidt & Bender 3-12 x 50 Police Marksman II LP rifle scope with illuminated reticle is replacing the Unertl MST-100 10x fixed day scope, previously used on both the M40A1 and M40A3. This dayscope is mounted with Badger Ordnance USMC M40A3 34mm scope rings, which utilize a standard ring in the rear and a wider MAX-50 ring in front. The standard front ring cap is replaced with a SPA-Defense B634 34mm Male Dovetail, as a mounting platform for the Simrad KN200 Night Vision Weapon Sight. The scope and rings are mounted on a Badger Ordnance 30 minute-of-angle lugged Picatinny rail.

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Comparison

ee also

Lists:
* List of weapons of the U.S. Marine Corps
* List of individual weapons of the U.S. Armed Forces
* List of modern weaponsRelated designation:
* M40 (field protective mask)
* M40A2 106 mm Recoilless Rifle
* M40 Gun Motor Carriage

References

External links

* [http://usmilitary.about.com/od/marineweapons/l/blm40.htm M40A1 Sniper Rifle] - Marine Corps Fact File