My 11 year old son will be able to big game hunt in Colorado this coming fall when he turns 12. In CO youths can not hunt big game until they turn 12. He will be hunting deer antelope. Anyways, he will be shooting a 260 Rem with a 20" barrel. I'm debating between the Barnes LRX 127gr and the Nosler Accubond Long Range 129gr. Any suggestions would be appreciated on bullets and powders.