by Shooting Illustrated Staff posted on October 21, 2010 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. ** Benelli MR1 In this article 5.56x45 mm, Benneli, semi-auto rifles Related Stories DPMS Panther 3G1 Gallery DPMS Sportical Gallery The Truth About Pistons Barrett REC7 Chambered in 5.56 NATO Gallery Auto-Ordnance AOM160 M1 CarbineAuto-Ordnance AOM160 M1 Carbine Gallery Most Popular Review: Beretta 1301 Tactical C Shotgun New Handguns for 2025 Armed And Safe Parenting Tech Wisdom: A New/Old Manual of Arms Knowledge Is Power Review: Heckler & Koch VP9A1 F pistol