The U.S. Army will officially introduce the carbine version M8 of its new M7 rifle in the 6.8 x 51 mm Common Cartridge caliber as early as December, according to the American Military Times, citing representatives from the manufacturer SIG Sauer. The company had developed the variant previously referred to as XM8 after soldiers complained about the mass and dimensions of the M7 from the Next Generation Squad Weapons (NGSW) program, especially when it was equipped with the standard signature suppressor and fire-control sight.
Already at the beginning of April, the Army had received the first delivery of the carbine. Compared with the M7 with a 13.5-inch barrel (343 millimeters) and a baseline mass of 3.8 kilograms, the future M8 with a shortened barrel by 3.5 inches (89 millimeters) weighs only 3.3 kilograms — of course again without the suppressor at 0.66 kilograms and the fire-control sight with an estimated mass of around 1 kilogram. The suppressor is likely to become even more important for signature reduction, as the shorter barrel presumably increases muzzle flash and bang of the high-velocity 6.8-mm ammunition with a hybrid-metal jacket for high chamber pressures.
Already delivered M7s could be converted into M8
To reduce weight, SIG Sauer also redesigned and lightened the bolt carrier group, slightly slimmed the barrel profile, and removed the folding mechanism of the shoulder stock. As a result, the stock is now adjustable in length only, as with the current M4 carbine. On this occasion, the suppressor was shortened and equipped with a titanium heat shield to reduce heat emission after prolonged firing.
Whether the M8 in the Close Combat Force, i.e., the branches of troops with direct ground combat duties, will supplement or fully replace the M7, is not yet clear. SIG Sauer notes, according to Military Times, that the already-delivered rifles could be relatively easy to convert to carbines. The NGSW program also includes the light machine gun M250 in the same caliber as the successor to the M249 Squad Automatic Weapon (SAW).
