almost daily there is a new cartridge created to be shoe horned into the AR platform. You can only do so much with the space constraints. Its a good thing in a way as there are as many opinions as there are Azzholes. Someone wants a flatter shooting more powerful loading, 6.X fills the bill, someone wants more than a 5.56 but is paranoid about bolt heads, magazines, platform longevity, and subsonic so whisper, BO, the next guy feels under gunned unless its a 400 grain chunk of lead as big as your thumbnail and there are 45 and 50 caliber guns. Then someone wants to shoot russian/commie ammo and there are uppers for that. Pick your poison if you can shoot, then any of them will work. Montana Marine did a quick load calculation on the Blackout with supersonic ammo, the muzzle pressure is 5,000PSI vs 11,000 PSI for a 5.56. To me this says lower dB's if even a supersonic load is fired inside a dwelling.
