I think a lot of it comes down to minutia. Sure a 7mm mag might beat a 300 mag after a certain distance.....sure a 300 mag can be loaded closer with say a 215 berger....and on and on...
Really that ONLY MATTERS if you are going to try and shoot something to those distances. If you are going to be more the norm...then 400 yards and in is all you need to be concerned about. Then choices also get harder because cartridges get even closer. If you really just want to be prepared then say a max of 500 yards.....so still close for a-lot of cals....
I do put some credibility on some information I think is relevant. A poster here by JJHACK found after shooting many animals and seeing many animals shot that a .30 cal just did better over a wide range of animals and circumstances (He was/is a PH in africa - 30-06), RBROS has culled more elk than most of us will be able to kill in many lifetimes - many at extreme ranges....he also finds the .30 cal to just kill better over a wide range of circumstances.(300 win, 215 berger). Scenarshooter has used a 308 to good effect as well....
I don't know how to prove anything of course. Obviously almost every cal can work just fine. My wife uses a 243 with my handloaded 95 gr ballistic tips....deer and elk have all been a non event. She won't use anything else. She can shoot it really well of course......
Personally I lean towards a 308 or a 30-06 for myself. I have a personal limit of 500 yards max on game. So both cartridges will work fine, however having an extra round in the mag is nice, lower cost of ammo / components is nice, availability of loaded ammo is nice - just picked up some .06 at Wally yesterday, weight of the rifles is nice, less recoil is nice, more practice is nice........YMMV
"You only know one thing for sure about a broken down old man........He's the survivor...."
