by Shooting Illustrated Staff posted on February 7, 2012 Optics Support NRA Shooting Illustrated DONATE Designed expressly for AR-15's chambered in .223 Rem. or 5.56 NATO, the scope is reliable, functional and fast. In this article .223 Rem., 5.56 NATO, AR-15, ballistic reticle, Nikon, riflescopes Related Stories Nikon M-223 1-4x20 mm WATCH: SIG Sauer M400 Tread Core Rifle Systems Releases The All New Hardcore X Series Rifles For 2015 Nikon Unveils New P-223 Long-Range Riflescope With Dual Ballistic Compensation Nikon M-223 Riflescope Most Popular New 2011 and 1911 Pistols for 2024 Body Language and Personal Defense Keeping The Proper Perspective 9mm Double Stack 1911 Pistol Roundup New Pistols for 2024 Review: Lipsey’s Smith & Wesson Ultimate Carry Revolver