Blain,
Check out http://www.teppojutsu.com/ . Marty at Teppo Jutsu can build you an AR-15 upper chambered in .458 SOCOM (what you see in my pic).
Check out http://www.teppojutsu.com/ . Marty at Teppo Jutsu can build you an AR-15 upper chambered in .458 SOCOM (what you see in my pic).