Re: 260 rem or 308 win
I have a 260 in a Savage LRP, I shoot the 140s and I am very happy with it, I agree with the former response, that you will learn regardless of your caliber.
I spent a considerable time researching the "best " caliber but after alot of consideration, I believed the 260 was a good compromise between being an efficient cartridge to shoot, accuracy, and excellent ballistics. There are other caliber choices out there that have better ballistics, but you may burn your barrel out before you find a nice load , or are just too expensive to shoot.
I consistency shoot out to 700-800 yards sub MOA, nothing record setting mind you but impressive none the less, considering wind and mirage (where I live) we always have one or the other or both,, that calber wont do you wrong, and the savage platform will perform well.
What kind of optics are you thinking of putting on your rig ?