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 Top 5 'Budget-Priced' .50 BMG Rifles 10 Budget-Priced .22 Rifles Under $200 Glock Models Retired for a New “V” Line How We Practice A Concealed Carry Primer Review: Tisas Night Stalker DS