RE: 260 vs 280, Pros/Cons
i have yet to find an obselete cartidge. they simply must be used for there purpose. the 6.5x55 i hear is a good cartridge but ive never looked to see if anyone have ammo for it. the 7mm-08 seems to be every where i look and seems like a good choice, though a .308 would also be a good choice. the 25-06 will perform for you as well and ammo is around for that as well. the .243 would also fit the bill
propmahn
save the world, reload your brass