The U.S. Marine Corps is replacing its existing sniper rifles with a newer model that fires a heavier, longer-range bullet. The new Mark 13 Mod 7 sniper rifle, a favorite of Navy SEALs is replacing the older M40 series of rifles. The result is a more accurate rifle with the potential to hit targets at nearly three quarters of a mile.
The M40 series of sniper rifles has served the Marine Corps for more than 50 years. Originally introduced during the Vietnam War, the Marine Corps purchased commercial Remington Model 40X bolt-action varmint rifles with heavy barrels, slapped on a Redfield 3-9x variable power scope, and gave them the designation M40. The M40 served in the Vietnam War and every conflict since then, progressively upgraded with new features such as a new Remington 700 action, fiberglass stocks, new optics, and other shooting accessories.
Despite the upgrades, the M40 series was limited by the ballistics of the .308 Winchester round. Although an effective hunting and military round, a.308 round rapidly loses energy after 700 yards. At 600 yards, a sniper armed with a M40 can expect a bullet to drop 105 inches short of the target, requiring upward compensation of 105 inches to remain on target. At 800 yards the drop balloons to 228 inches, and at 1,000 yards the drop is 421 inches. This loss of energy also affects wind drift, with .308 requiring 53 inches of wind correction in a five mile-per-hour wind to hit a target at 1,000 yards. The M40 series’ maximum effective range is about 1,000 yards.
The fewer corrections a sniper must make to hit a long distance target the better, and sharpshooters accomplish this by using a heavier, higher-power round. Unlike the older .308 round, the bigger .300 Winchester Magnum is effective out to 1,300 yards. It requires only 246 inches of vertical correction at 1,000 yards, and 40 inches of horizontal correction at 1,000 yards in a five mile-per-hour wind. The heavier round also hits with more energy at longer ranges, making it more likely to incapacitate the target. The .300 round’s maximum range is about 1,300 yards.
Now, according to Military Times, the Marines are finally switching to a .300 Winchester Magnum platform. The Mark 13 Mod 7 rifle, originally used by Navy SEALs, is a Remington 700 long action in a lightweight, skeletonized chassis. The Mark 13 uses the Nightforce ATACR rifle scope with Horus Tremor3 reticle. The reticle features marks for quickly estimating range to target, compensating for bullet drop and accounting for wind shift.
The Marines plan to purchase 346 Mark 13 Mod 7 rifles for $4.3 million. The rifles are built by Naval Surface Warfare Center, Crane division, in Crane, Indiana. NSWC Crane is responsible for several Navy and Marine Corps small arms projects, including the Mark 12 Special Purpose Rifle.