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 SHOT Show 2025 Range Day Roundup Review: Walther PDP Compact Steel Frame AR Lower-Receiver Build: Trigger Group Installation Updating The "Pie Chart" Target First Look: Kel-Tec PR57 Pistol First Look: Staccato HD Pistols