M40 (rifle)
The M40 is a sniper rifle used by the United States Marine Corps. It has two major variants — the M40A1 and the M40A3.
Each weapon is hand-built by USMC armorers at Marine Corps Base Quantico, using components from a number of suppliers. New A3s are being built, and A1s are upgraded to A3s as they rotate into the armory for service and repair.
| Specifications |
| M40A1 | M40A3 |
| Caliber | 7.62 mm NATO (.308 Win) |
| Weight | 6.57 kg (14.45 lb) | 7.5 kg (16.5 lb) |
| Overall Length | 1.117 m (43.97 in) | 1.124 m (44.25 in) |
| Barrel Length | 610 mm (24 in) |
| Barrel | (to be done) | Schneider Match Grade SS #73 |
| Lands and Grooves | 6 | (to be done) |
| Twist | Right Hand, 1:12 | (to be done) |
| Trigger Pull | 3 to 5 lbf (13 to 22 N) |
| Magazine Capacity | 5 rounds |
| Sight | Unertl 10x with Mil-Dots and BDC;
specially designed for USMC |
| Stock | McMillan fiberglass | McMillan Tactical A4 |
| Max Effective Range | 915 m (1000 yd) |
History
During the Vietnam war, the Marine Corps decided they needed a standard sniper rifle. After testing several possibilities, they ordered 700 Remington Arms Model 40x rifles (target/varmint version of the Model 700 bolt action rifle). 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 tweaks, replacing the original wood stocks with McMillan fiberglass stocks as well as replacing the original Redfield scopes with Unertl scopes.
The US Army also uses the Remington 700/40x action as the basis for its M24 SWS (Sniper Weapon System). The primary difference between the two 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 mm/08 Remington, .243 Winchester), the Army M24 uses the long action version of the same rifle (designed for full-length cartridges, such as the 30-06 Springfield, and "short" magnum cartridges, such as the 7 mm Remington Magnum, .300 Winchester Magnum and .338 Winchester Magnum). The US Army reasoning behind this decision was to allow them to reconfigure the rifle in the larger, longer-range calibers if necessary. Whether or not they will do this is anyone's guess, but one might note that the British Royal Marines, among others, have adopted rifles in .300 Winchester Magnum and .338 Lapua as special purpose sniper rifles.
Upgrade
The upgrade includes the installation of the Schneider Match-grade barrel; a target-grade steel floorplate and triggerguard assembly; the McMillan stock, with adjustable cheekpiece and length of pull; new scope bases and rings; and a Harris bipod and accessory rail.
See also
