Did you consider accomodating the rim for the .45 Auto Rim round? I ask because as well as using a 1911, I also use the 1917 Colt and S&W revolvers, and stocked up on Remington .45 Auto Rim brass long ago. I load a 250 gr. flatnose made for the .45 Colt with a rather hefty charge of Universal Clays. I've tried loading that same bullet in the ACP case, as well as some of the heavier .452 jacketed bullets, and they bulge the ACP case, and do not in the AR case, and, I can put whatever crimp I want on the AR case, letting me get a more efficient burn with slower powders. Shooters long ago found that the .45 Schofield cartridge, (the substitute standard in the Army for the .45 Colt cartridge) being shorter, was a lot more efficient than the Colt cartridge, and the .45 AR case makes even more efficient use of the svailable space. I'm sending my Ruger .45 Blackhawk back to be fit for another cylinder specifically to have it modified for the AR cartridge, and I'm eyeballing a little Marlin 94 to see what it'd take to convert it. Do you get the notion that I'm a fan of the round?
Something to consider.......