by Shooting Illustrated Staff posted on April 11, 2011 Guns Support NRA Shooting Illustrated DONATE Resurrecting the 6x45 mm cartridge, Spirit Gun Manufacturing's SGM-A41 is a high-performance, yet practical, take on the AR platform. In this article 6x45, AR, semi-auto rifles, Spirit Gun Manufacturing Related Stories Spirit Gun Manufacturing SGM-A41 Barrett REC7 in 5.56 NATO Gallery Colt Match Target M4 Case-Head Swipe Wilson Combat SPR Gallery 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