Tikka Varmint in 6.5X55 swede.
Nothing wrong with the 260, I just have a nostalgic respect for what the Swede has proven over and over for more than 100 years.
On the Chuck Hawks page he summed it up that the 6.55x55 will do everything and more than a .260 but he doesn't say too much about the difference in recoil etc. He just prefers the 6.55x55 because it will shoot just as good and has a little more options on the high end of bullets.
I would generally agree with Dan, with one exception. Older actions with a bit of "slop" in the boltface like the 1917 Enfield or the 98 Mauser will work with both 6.5x55 and .308-based cases. I know. I've done it.
The same is not true of tighter modern actions like the Remington 700 or the Savage, however. In those cases, a boltface that works for a .308 would likely be a hair too tight for a 6.5x55 to work reliably.
Agreed, It is not well known, but the 6.5X55 is a hair bigger at the base than a .308 so those contemplating a build on a 700 LA would benefit from opening the bolt face. Buying a factory gun chambered in the Swede would not be an issue.