Guys: Sorry, but the 260 is marketted to be 'close enough to the 6.5 Swede'. As one of the first articles on the 260 said, this comes close enough to the 6.5 to be a hunter's dream. Why not go for the real thing?
OK, if you want to come close enough, then the 260 is as close as you're gonna get without going to the Swede. Actually, the 260 case is about the same size as the 6.5 Carcano, which was not a bad round, only shot through crummy rifles.
To me the difference is between shooting the 06 or the 308. You can probably push one to get close enough to the other so that it won't matter but what you do find in the 260 vs 6.5 Swede comparison is that the later, the Swede, will perform better with heavier bullets the same way the 06 performs better than the 308 with heavier bullets.
Most American ammo manufacturers like to load medium weight bullets in the 260 and the 120 grain 6.5 is a good example, as is the 150-165 grain 308. But, the real performance in the 6.5 or the 06 comes from the heavier loads. Most 6.5 Swede ammo carries a 140 grain bullet and it is an excellent all around cartridge. If you want to shoot long range you can go to the 155-160 grain loads and there the Swede excells. The 6.5-06 is an excellent example of the long range capabilities of the 155-160 grain 6.5mm bullet. The same goes for the 06's 190 grain bullet - it is an excellent long range performer in the 06 and excells beyond the 308.
Surely there is always something to be said for lighter weight and easier to carry rifles with sufficient power to take the game you hunt. But, I've always felt that if I can't haul the load I don't have any business being out there however, I have changed my tune just slightly over the years - now, instead of shouldering a scoped military M38 6.5 Swede, I've customized it with a lighter stock, but it's still a military rifle in civies.
Another thing I don't care for in these new lightweight sporters is that they start throwing their groups after the 2nd shot (as in rapid field fire). The manufacturers say that you don't need or shouldn't have to use any more than one shot or just one with a follow-up but hay, why lose that capability when a military Swede will shoot whatever you want to put through it all day long and keep on grouping the way you want it to.
Also, the commercially made european ammunition is made to original military specs, not the loaded down 'liability loads' the American ammo makers consider acceptable. My Swede shoot only Sellier and Bellot, unless I want to reload for it. Tain't ne'er gonna see no Remichester down the tube, nosir.
Just my 2 cents worth. Mikey.