A lot of it depends on which bullet you want to shoot. If you want to shoot the 140's(which IMO is the best) then I would stay with a 6.5 mm cartridge. If you want to shoot the 120's then I would drop down to a 25 caliber cartridge. So IMO a lot depends on the bullet you want to shoot.

You can easily load the 6.5 Swede up to 2800-2900 fps with a 140. and maintain a lower pressure than the 260 Remington. You can push the 6.5X284 a bit faster but that is also under higher pressure and lower barrel life.

I like the Swede. I am looking at one right now in a Cooper Laminated Varmint model. I have narrowed it down to the 260 Remington, 6.5X55 Swede, and the 6.5 Creedmore. Take a look at the Creedmore. Hornady makes very good match ammo for that rifle at a great price(about $24 a box).

IMO the problem with the 260 Remington is the lack of good brass. You can buy Nosler but it is over a buck a pop(that is as much as Hornady loaded 6.5 Creedmore). With the Swede you can buy Lapua brass, and that is also good stuff, and considerably less than Nosler brass.

If you want something different then take a look at the Creedmore before you make a final decision. And look at the velocities they attain at the operating pressures. The Creedmore is a decent cartridge.

If you decide to rebarrel to a Swede make sure you talk to the smith about the throat. Most standard Swede's have a long throat. You might want to rethink that. Tom.