222 all the way, uses less powder 22 grain +-load,gets the same results, flat shooting, no kick ,see in the scope what you hit,takes red not leagle but it does fine round.If you want to fire FMJ the 223 is for you MOD will sell you tuns ..222 is a fine round ask the benchrest boys.
try a 40 grain head .224
nothing can compete apart from .17 which is a necked down .222 ,but if its windy instead of a .17 use a catty lol
cheers andy