Although this topic has been around for the last 50 years or so, as I remember,
it's always a good one! And this is the only thread I remember that I agreed with what's said in every post. Lots a good opinions, each valid, so Mr. OP, unless you have a strong preference for one over the other, it would seem all you have to do is find a great deal on a rifle and as long as it's in either cartridge you're good to go!
Now for my 2 cents...
Sorry, I always got something to say.
Remember now, growing up I read everything J.O'C wrote; several times! He said it, I believed it, no argument about it! And although most people associate him with the .270, as I remember he was actually quite fond of the 30/06. He once said something to the effect that he didn't see any reason for the .308 in a bolt action rifle. Also, Elinore, who generally used a 7x57, used a 30/06 as her "big" rifle for Tigers, the big bears and such. Quite a recommendation.
That fact notwithstanding, I've never been able to keep a 30/06 sporter long. A M70 Featherweight was re-barreled to 270 and a sporterized 1903 was rebored/rerifled to 338/06. The ones before that just disappeared.
Sometime in '06 I realized I didn't have an '06 sporter so picked up a used M700 Mountain Rifle in that caliber for a good price. Cleaned it up, it seemed like it wanted to shoot, I did what I normally do to my bolt guns and now it shoots just about whatever I feed it into very small groups. That is just what I remember about my 30/06's; they generally shoot good and whatever I hit with them dies. The cartridge is steady, reliable and boring in it's suitability as a g.p. round.
Counting that M700 I own one sporting rifle in each caliber; 30/06 and .308. I've got a lot more 7.62's and 30 cal's in military guise but that's not the subject here. I also own one belted magnum; a 300WM. My philosophy is, pick a velocity you like, mine is 2800 fps +/- 100 fps or so, and work up a load for a given bullet weight: i.e. .308/150 gr @2800 fps +/-. If I feel the need for something with a little more or less "whack," I go up or down a cartridge or so. i.e 30-06/165 gr. @ 2800 fps +/-, or 300 WM/180 gr. @ 2800 fps +/-. Is this logical? maybe... Is it reasonable? could be... do I adhere to it? almost never!
But what the heck... a man got to have a basis for his actions!
And this sounds reasonable to my wife when I'm spending money trying to round out my stable of rifles in any caliber; 25, 26, 28, and so on.
My 308 is a M99A that has never shot as well as I would like. I've killed a number of deer with it and it does a great job, and works just as well at 300 Savage levels. I have another M700 that started out as a .308, but is a .260 now, much better use for a short action... Ol' Jack would be proud of me!