I had a .22-250 I was using for varmit and hogs. It was a wonderful caliber unless a 250+ hog or deer showed up. While a .22-250 can kill them with a perfect shot, I felt way undergunned. I sold it for a .243 Rem 700 mountain rifle. You can shoot 55 grain (flatter than the .22-250) and up to 100 grain bullet works great on deer and hogs.
It is an awesome caliber. However, for your .30-06 you can purchase 125 gr bullets (from Remington) for varmit and use 150gr+ for hogs. If you own a .30-06, you really don't need any other rifle for any game. If you need something other than the .30-06, it's just becuase you want one, not need one.