I kinda sorta agree with the beekeeper on this. Any good expanding .223 projectile will take a small or large whitetail with absolute perfect shot placement. If you've hunted deer as much as I have then you know that perfect shot placement happens all to infrequent. Any good center fire traditional deer rifle will out perform the .223 most of the time. .243 and up is my recomendation. The bigger bore rifles,.25-06 and larger, will give you proper penetration on about any angle of shot. I can not recomend the .223 for them big ole Missouri whitetails with any load. I have killed white tails with .22 rimfire pistol and rifle, 9mm, .357, .30-06, .25-06, .30-30, .45, .44, 12ga., .410, 2 and 3 blade broad headed arrows. They all work, just some work better than others. The standard .30-30 has killed more North American game than any other calibre. That tell you anything? Good luck.