I'm going to give you a counter argument to the 6.5 Creedmore in favor of the .308 Winchester.
First and foremost, any long range shooter who relies on ballistics of a given cartridge to save his bacon doesn't know his business. I say this for the very simple reason that I have shot with some of the very best in the nation at Long Range Highpower and the bottom line is this. You either know your come-ups for a given range or you don't. You either have wind dope for a given range/conditions or you don't. Make mistakes in either case at ranges beyond about 600 yards and I don't care what medium weight cartridge you shoot. You will miss. So knowing your gun and load is about 10 times as important as cartridge selection. I've shot in many many unlimited 1,000 yard matches where people shooting .308s beat 7mm Magnums etc.
Secondly, the 6.5 Creedmore has a fairly short barrel life of less than 2,500 rounds or so. This is about half of what you can expect in a .308. Anyone who thinks they are a long range shot and hasn't burned out a barrel or two doesn't know their business. It takes thousands of rounds to learn long range shooting. The 6.5 is a crummy round to learn the game with for this reason. Wait? Barrels burn out that quickly? Yes...on long range rifles they do. The throats erode and you won't be able to hold the 10 ring at 600 yards and beyond. You will never see it if all you shoot is 100-200 yards.
Third, people like to compare the ballistics of a 6.5 140 grain bullet to a Sierra Match King 169 grain bullet. Step up to a 175 or 190 grain (190 is a superb .308 long range bullet) and the differences in BC and other factors begin to fade. So if you handload you can shoot High BC bullets like Berger's and get close to the ballisitic performance of a 6.5 without all the excess barrel wear etc.
Yes, recoil is a little more in a .308. Have you held a Ruger Precision Rifle...its a heavy SOB. Recoil will not be an issue with this gun.
Forget things like ammo availability. The .308 wins that hands down.
So you see my reasoning. The .308 is no slouch and with good handloads and good dope data and a shooter who knows how to read conditions will perform right alongside the 6.5. Is the 6.5 a better round? On paper yeah. But like most shooting stuff the difference between paper data and actual practical utility gets blurred quite a bit when you look and see actual user results...