Patriot Ordnance Factory Revolution 308 Winchester 16.5in Black Anodized Semi Automatic Modern Sporting Rifle - 20+1 Rounds - The Revolution is POF's 308 Winchester that handles like a 5.56 - because it is the same size and weight as one by using a 5.56 bolt carrier and other 5.56 parts allowing for a shorter overall receiver size and reduced weight. The Revolution features many 5.56 parts; such as charging handle, bolt carrier, cam pin, buffer, heat sink barrel nut, handguard, and 5-position gas piston operating system. The barrel extension, bolt assembly, upper, and lower receiver are the exact same size as those on an AR15. This model is built on the Gen 4 lower receiver with a NP3 nickel metal finish, a 16.5in M-Lok MRR free-float handguard, and POF's standard 4.5lb drop-in trigger. Caliber: 308 Winchester, 7.62mm NATO 16.5in Match Grade Nitride Heat Treated Barrel 14.5in M-LOK MRR Free Float Rail System, Optic Ready E2 Dual Extraction Technology Chamber Five Position Adjustable Gas Block Triple Port Muzzle Brake Ambidextrous Bolt Release Ambidextrous Safety Selector Ambidextrous Bolt Catch Ambidextrous Magazine Release 7 Position Anti-Tilt Buffer Tube Comes with One Magpul 20-Round Magazine