I think I'd opt for the 280 in this rig. The 30/06 is a great round, but I have one. The 308 is great, but the 30/06 gives just a hair more ... not enough to make a difference to the game, but it can be measured. If I didn't already own two 30/06's I'd go with that b/c of ammo availability.

But I don't yet own a 280, always wanted one, ...is a great round and caliber with a ton of bullets out there for the handloader.