by Shooting Illustrated Staff posted on October 13, 2011 Guns Support NRA Shooting Illustrated DONATE Primary Weapons Systems goes out of the box in AR design. In this article 5.56 NATO, 7.62 NATO, AR, Primary Weapons Systems Related Stories Primary Weapons Systems PWS MK116 and PWS MK216 Carbon-Fiber Rifle Round-Up AR-15 Muzzle Brakes Gemtech Suppressed Bolt Carrier 14 New Rifle-Caliber Pistols for 2019 Most Popular So What’s Next? Jim Cirillo’s 1-2-3-6 Drill Be More Than A Bodyguard Which Shotgun Safety Is Best? Grocery Stores Lining up for Ammo Vending Machines Review: Smith & Wesson Model 1854 Rifle