.270 Win and .300 Win is all you need for deer elk and black bear.
If you handload, 130gr 277 and 180gr 308 bullets @ 3000 fps are in essence ballistic twins. You can have two Mod 70s made up with the exact same LOP, exact same trigger pull and in essence you have "one rifle." I know, I have that same set up a 300 Win by Charlie Sisk and a 270 by Kevin Weaver. And I'm having a second set built right now by Patrick Holehan.