I don't see an answer from Jake. Anyway, a .243 will suit your needs very well. It's about bullet choice. You will have to find a heavier bullet weight with a controlled expansion for whitetail and a light and tough bullet for the predators if you want to save the hide. If you are a very skilled marksman you could even go down to .223 with the same bullet specifications as before mentioned. Just make sure your rifle of choice likes both combinations. If you reload, you could do this with a .30-06 also.