by Shooting Illustrated Staff posted on October 13, 2011 Guns Support NRA Shooting Illustrated DONATE ** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. ** 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 New Handguns for 2025 Tech Wisdom: A New/Old Manual of Arms Concealed Carry Is A Lifestyle 10 Budget-Priced .22 Rifles Under $200 Ruger Acquires Anderson Manufacturing Knowledge Is Power