Originally Posted By Joenavy85:
Some may discredit this because it came from wikipedia, but I emailed it to my cousin (a Marine Gunnery Sargeant) who verified the info with one of his friends who works in Quantico.
Action: The M40 has always been based on the proven Remington 700 Short Action with .308 bolt face and this is no different in the M40A3. These actions 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, 6-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 six mount flush cups, two on each side front and back and one each on the front and 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.
Snipers utilize a M40A5 with tripod and suppressor while training at the Mountain Warfare Training Center
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× 50 Police Marksman II LP rifle scope with illuminated reticle has replaced the Unertl MST-100 10× fixed day scope, previously used on both the M40A1 and M40A3. This dayscope is mounted with Badger Ordnance USMC M40A3 34mm scope rings, which use 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 DD Ross 30 minute-of-angle lugged Picatinny rail.
Quick inject: The Marines measure differently. They measure from the recoil lug, so in reality the barrels are 25 inches.