I' ve hunted with all four calibers mentioned and wouldn' t feel handicaped by any of them. I' m a big .308 fan, but since the T3 only comes in a long action, I' d go ahead and use a full length cartridge. Any of the four will kill anything in North America, but I' ll vote for the 7mm mag. It' s a nice flat shooting cartridge with plenty of energy for any long distance shot you may have the need to take.