As several mentioned....the .243 is a very good Caliber and it is plenty good to take down a Whitetail Deer,the 7mm-08 is very close to the same size and has more choices in a heavier grain bullet.I have both Caliber Rifles and have trouble choosing which to use when Hunting....the Browning A-bolt Hunter I used this year is very Accurate and has put down more nice Bucks and Doe's than any of the Rifles I have.The main thing as Sheridan mentioned is "Accuracy" and to Target Practice a lot with the Rifle of Your choice....a .223 is just as deadly to a Deer in the right Persons hand that knows how to make a good shot placement.