by Shooting Illustrated Staff posted on October 21, 2010 Guns Support NRA Shooting Illustrated DONATE 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 Tech Wisdom: Ancient Ammo Review: Smith & Wesson Bodyguard 2.0 See Your Sights Classic Guns: USMC M40A1 Sniper Rifle The Return Of The Lever-Action Rifle Avoid It If You Can