Believe it or not, I have all 3 of the calibers you have listed. For my vote, the 280 is the one to choose. It is right on the heels of the 7 mm Mag, performance wise, and is at least as accurate as either of the others. The only fly in the ointment is ammo availability. It's just plain hard to find 280 ammo some times. For ammo concerns, the 270 or 308 is better.