Aside from the "killin power" of various cartridges on deer, there is another consideration that should be considered. -- Most of us when standing on our hind legs and shooting at a target,(or deer) will shoot a 223 or similar much more accurately than an - 06 or similar. And that probably goes for shooting from a rest as well.
My first deer rifle was a .243, and before I shot any deer with it I had killed a bunch of chucks, jacks, coyotes, squeaks, etc. I could stand shooting off-hand at a hundred and keep most of my shots in a 4" bull. I killed about a dozen deer with it in the first five years or so, most of them dead on the spot. THEN--- I got a good deal on a 270, same model of rifle, and started using it for deer and elk. I immediately started botching things, made a mess of some pretty easy shots, and had to chase some bucks around to finish them. I just don't shoot that rifle as well, and I know that there is no good reason for it. jd