The 500 Auto Max was developed by Big Horn Armory in Cody, WY as a rimless version of the 500 S&W Magnum and was designed for an AR-500 platform. Big Horn Armory already had a highly successful line of lever action rifles chambered for the 500 S&W and the next step was to adapt to the AR platform, which represents the best in current firearm technology and known to almost all sport shooters.