The M40 sniper rifle was developed during the Vietnam War, ordered by the Marine Corps based on the bolt-action, magazine fed Remington Model 700 7.62mm rifle.
U.S. Marine Corps Sgt. C.J. Quinland, 3rd Battalion, 2nd Marines, firing an M40A3 sniper rifle. Photographed on the flight deck of the USS Kearsarge, 17 June 2003 as the Kearsarge returned home from a deployment in support of Operation Iraqi Freedom.
Today in WW II: 1 Aug 1943 Ploesti Raid: 178 B-24 Liberator bombers flew over 1200 miles from a base in North Africa to Ploesti, Romania for a daring, low level attack on oil production facilities. More↓
The M40A1 sniper rifle is a highly capable and accurate bolt-action rifle with a built-in five round magazine of 7.62mm ammunition. It is made from a commercial competition-grade heavy barrel, McMillan fiberglass stock and butt pad, modified Winchester Model 70 floorplate and trigger guard, and modified and lightened trigger with adjustable pull in the range 3-5 pounds. In addition, each stock is epoxy bedded for accuracy. The USMC Unertl 10x scope is standard on the M40A1.
A Marine sniper and spotter zero the M-40A1 sniper rifle during Operation Cobra Gold 2000, Ban Chan Khrem, Thailand, 19 May 2000. Marines are assigned to 1st Battalion, 7th Marines, 3rd Marine Division.
In 1966, during the Vietnam War, the USMC ordered Remington Model 700 7.62mm rifles with Redfield 3-9x scopes as a long range sniper rifle, replacing the M1952 USMC Sniper Rifle that was based on the Army M1C. The Marine version of the Remington was designated the M40. By the early 1970s, the Marines had established their own upgrade program consisting of modifications and improvements based on field experience with the M40, such as replacing wood stocks and upgrading the scope. The improved M40 was designated the M40A1.
The M40A1 was manufactured by specially trained armorers at the Marine Corps Marksmanship Training Unit (MTU) in Quantico, Virginia. To be accepted, each weapon had to shoot less than one minute of angle (MOA).
The U.S. Army also uses the Remington 700 action, as the basis for the M24 Sniper Weapon System. However, the USMC M40A1 (and A3) rifles are based on the short action version of the Remington 700/40x while the Army M24 uses the long action version of the same action.
M40A3 Upgrade to the M40A1 Sniper Rifle
The M40A3 is an improvement to the M-40A1, incorporating twenty years of field experience and technology advancement. Development started in 1996 and field use began in 2001. While still based on the Remington short action Model 700 receiver, the M-40A3 has many upgrades and changes:
Schneider Match Grade SS #7 barrel
McMillan A4 Tactical stock, with adjustable cheek & length of pull.
D.D. Ross floor plate & trigger guard
G&G Machine modular M1913 MIL-SPEC rail system
D.D. Ross base with G&G Machine rings for scope
The action is glass bedded into the stock with aluminum pillars, but the barrel floats, attached only to the action. All new USMC sniper rifles will be built to the A3 specification; as M40A1 rifles rotate in for Armory repair, they will be upgraded to A3.
The rifle is optimized for accuracy with M118 Long Range (LR) 7.62x51mm NATO (.308 Win) Match Grade ammunition.
M40A1 and M40A3 Sniper Rifles Scopes and Optics
The M40A1 and M40A3 sniper rifles are equipped with a fixed USMC Unertl 10x scope (upgraded and adapted to match when used with the A3). The M40A3 optionally has an AN/PVS-10 Sniper Night Sight (SNS) attached to its modular rail.
The AN/PVS-10 is NSN 5855-01-410-8979, and the technical manual is TM 11-5855-303-12&P. The AN/PVS-10 is used only on the M40A3 and the Army M24 sniper rifle. Although called a "night sight" is has day/night capability. The Technical Manual for the AN/PVS-10 SNS is TM 11-5855-303-12&P.
Recommended Books about Sniper Weapons and Tactics
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