I started an AR-15 build in 1990 from an Olympic Arms lower receiver. I am continuing on that AR-15 platform with a new 458 Socom upper from Tromix. I'm convinced that 223 is not adequate man-stopper without multiple hits so I have chosen the "45-70 glory wrapped in AR-15 clothing". I dived right in and bought all I need for this caliber for just under $2,000. I'm excited to develop loads for this weapon maybe up to 525 gr "pile driver" from Beartooth Bullets. Has anyone done the same build? I've attached some photos.