A quality .223 bolt gun with a fast twist barrel in a "close-to" blueprint of your favorite hunting rifle is worth the investment. .22 rimfire aside, I shoot a lot more .223/.223AI rounds every year than I do all other centerfire rounds combined. About any time I'm shooting there's a 223/223AI along for the ride.
Just my opinion, but I think a manufacturer should make a fast twist .223 version of every rifle they produce.
