ORIGINAL: SeraphG
My oppinion is, if you want to nail something in an AR-15 config, lay down the dough to get it chambered in 6.5 Grendel, .308 or .300 Remington SAUM. That would be the only ethical way I could see to deploy that platform in a big game scenario (and its an option I am currently considering myself).
My next AR will be a DPMSchambered for .243 Win.