Again, thanks for the replies, I read them all very carefully and sometimes I read them a couple of times.
From what I have learned I feel that there isn't enough difference in the .260 Rem, 6.5 Creedmoor, or the 6.5 Swede to make a decision based on the cartridge alone.
As for a modern cartridge versus one 100 years old, well, I have a .30-06, not a .270, not a .308, but a .30-06. Why? It is part of my family's approach to firearms, and everyone has always said since I was a little feller that a .30-06 is the first hunting rifle you get and if you can never afford another you will be in good shape. Now granted when I was even smaller I was given a .22 LR, everyone has to have a .22 LR. I have shot many a ground hog and other pests with that rifle.
So, now it may come down to my preference of the rifle make. I was raised on Browning, Remington, and Ruger. I have strayed from the pack and have a CZ and really do like it a lot. I have always wanted to give Weatherby a try as well.
So, I start to look at things like barrel profile and weight, magazine, floor plate, safety mechanism, bolt lugs, controlled feed or not, etc.
The question as to weather or not I should factor in the ability to buy off the shelf ammo, well it is important to me. For one thing, I like to have 200 rounds of ammo for any new caliber that enters the collection. I like it to be high quality ammo as well. Yes, in a hunting rifle, I may never shoot it, but that is just me and what I want.
I also use the factory ammo to set my expectation. If the rifle shoots match ammo well then I have a place to start. I am very lucky, my Browning .30-06 and my CZ 527 are both what my brother labeled "ammo insensitive". No matter what we put in them they grouped the same. Once in the .30-06 my brother shot three rounds, one 110 grain handload and two 165 grain factory rounds, and all three made a little mickey mouse shape. He said he wished his 300 Win Mag would do that, he said on it the point of impact would change inches with the slightest change in the load.
So, again thank you. I now have to think about the rifle and action, etc, etc.
Please continue the discussion, I don't want to stop anyone who has interest. It will really be months before I make a decision, several months. I plan way ahead, get things figured out, and then watch for deals or changes in the platforms.