This topic comes up at least once a year. The 243 is a fast, flat, accurate caliber, more than big enough for whitetail of any size. If you can't hit the vitals of a deer, no gun will be big enough. Any deer taking a .243 slug through the lungs is dead, period. The 30-06 is a fine caliber but it has it's own disadvantages, such as a tremendous kick. A friend got his first deer this year with his '06 and he also got a nice slash between his eyes from his scope. Yes, I know he wasn't holding it properly but that's what happens sometimes with a big-kicking gun, it makes flinchers of people.

If anyone prefers something other than the 243 that's fine. But to say it's too small is simply incorrect. People take Mule deer with 243's all the time.