Re: 30-06 or 243 deer?
I live and hunt in western canada, and am a huge fan of the .243 caliber for mule and whitetail deer, (and black bear)
using Federal Premium NP I have taken deer at 320 yards ( rangefinder) with one shot that dropped within a few feet.
I like the lack of recoil, flat trajectory, easy availability of ammo, and don't feel a need to move up ( I have also had 30.06 / 7mm Rem)
I know a lot of other people who are as confident as me, in depending on the 243 for deer.