You can get an AR-15 chassis in 223WSSM which out performs the 22-250 and is actaully closer to the 220 Swift.
Mike Milli will build you a custom upper with guarateed accuracy for just slightly less than a factory upper.- He pioneered the system that Oly now sells
www.dtechsuperstore.com
http://www.olyarms.com/index.php?pag...mart&Itemid=37