I have to agree that a 223 would be a great choice foryou. But out of your choices i would pickin thi order 270, 30-06, 308. You can get rounds for them about anywhere and for a decent price. Also they dont have too much recoil like a mAgnum would have and they all will make a major mess of a water jug or watermelon or punkins or whatever else you decide to shoot (im very fond of shooting at cheap cans of soda at long ranges for the explosion you get whan you hit them).