I just ( this very day) did some reading on the .260, and am of the opinion that it doesn't hold much if anything over the old 6.5x55 Swede.
If you're looking for something in that size, then look closely at the 6.5 Swede.
Grab yourself a book like 'Cartridges of the world' or an old SPEER reloading book (it shows ballistics and bullet drop at 300 yds, with a 200 yd zero), even Nick Harveys reloading book which shows the maximum 2" point blank zero, and compare the real life statistics of your favourites. The Swede compares very favorably with them both.
I had a lovely Factory Carl Gustaff left handed Sporter in 25.06 and with 90/100 grners, was a very flat shooter, and was a great Goat, Fallow Deer rifle out to 300 + yds. With 120 Sierras, it was devistating, but no better than the 6.5 that had less recoil. The 25.06 is not known for it's abillity to shoot much heavier than 120 gn. where the .260 and 6.5x55 will most certainly.
So in my humble opinion, ............ buy what you want, they're all good.
