viking499,
You never really said what the purpose was for this rifle you are considering getting, and since everyone seems to think it is for hunting, I will approach it from a LR target shooting viewpoint. First, the 7-08 is a bit under-bore for the caliber. If going with a 7mm caliber, then there a MUCH better options available using cartridges with more case capacity (.280Rem and .284Win). Next, the .260: a very good cartridge that is slightly hampered by the lack of quality brass available for it. Many .260 shooters are either necking up or necking down Lapua brass to solve this problem, but it's a PITA. Also, once you start using the long, heavy, high BC bullets in the .260 case, you now have a cartridge that no longer fits in a short action receiver, unless you seat them deep, which cuts into your marginal-to-begin-with case capacity. Lastly, the 6.5x55: As previously pointed out, factory ammo is seriously loaded down in deference to Norwegian Krags that are still occasionaly found. It is long action cartridge, so load them 139gr to 142gr bullets out as far as you want, and give yourself the benefit of the added case capacity. Lapua and Norma brass are readily available, and even though the Lapua brass is the cheaper of the two, it is superior to Norma in every way. 2950fps is easily (and safely) doable with RL22 in a 28" barrel, and 2925fps with several other powders (H4350 and N160) I have tried. Hope that is of some help.
Don