a 243 will out perform a .223 on any level,speed, accuracy,no comparison,but the 223 uses less powder to reload, some rifles cannot shoot the mil surplus ammo without problems,also the mil surplus ammo has increased in $ & availability,go to rem website & compare some different calibers on the ballistic program to see the differences ,lord if $ was no object i would have several rifles in every caliber,there is no bad choices,only better & each 1 may not be rite for every shooter ,mike300wm