Knight's Armament SR-25

The SR-25 (Stoner Rifle-25) is a designated marksman rifle and semi automatic sniper rifle designed by Eugene Stoner and manufactured by Knight's Armament Company.

The SR-25 uses a rotating bolt and a direct impingement gas system. It is loosely based on Stoner's AR-10, rebuilt in its original 7.62×51mm NATO caliber. The heavy 20-inch (510 mm) barrel is free-floating, so handguards are attached to the front of the receiver and do not touch the barrel.