I have a Stag .223/5.56 AR with a 18 fluted free floating barrel. The twist is 1 to 8 requiring heavier bullets. I looking to put a 20 + in bull barrel on it with a 1 to 9 twist and no flash hider but a crowned muzzle. The current and intended barrel is and will be free floated. I've mad other mods to the gun as ind trigger and stock as my enjoyment is tight groups at 100 yds + and as a back up varmint gun to my bolt 22-250 . Looking for suggestions on barrel make to fit my needs . Thanks