I agree with 2muchgun, if you're set on the Tikka, which only has the one length action, than go for the '06. I'm not saying anything bad about the .308, in fact, it would be my round of choice but only in a short action, light weight gun that I'd use for deer or bear mostly but with the right bullet it would work just fine on elk too. I've used the 150 grain Sierra pro hunters for deer but I'd go to on of the premium 180's for elk or even moose. Really either round will work fine just choose the right action to fit it.