if youre gonna do that get a .308 variant, 223 is a pretty small round to be considered a true "sniper's" round.
.308 has a longer reach and carries more energy over that longer range, so if you wanted to do any hunting with it you'd be in good shape.
223 isnt going to bring down most large game very easily. i hunt pigs with my 223 AR, but that's as big as id go.
look into 270 hunting rifles as well, i was thinking about getting a rifle in that caliber next. probably something bolt action and high-end, THAT'S a good and versatile hunting rifle. AR ammo is cheaper and easier to get in bulk though, so better for fun shooting and plinking.
and soulskier has a cool point about the Garand. that's a rifle that'll probably be on my list for a while, but ill eventually get one because theyre super sweet, i just cant justify it now for some reason. they are AWESOME though, ive shot them a couple times. rest assured, when i buy my first house after law school one of the first things im going to do is get a burly gun safe with loads of space. once i have a place to safely store lots of gear, im going to start getting more long guns, and a garand will definitely be in there.
"Just ahead, over the rolling wheatfields all golden beneath the distant snows of Estes, I'd be seeing old Denver at last. I pictured myself in a Denver bar that night, with all the gang, and in their eyes I would be strange and ragged like the Prophet who has walked across the land to bring the dark Word, and the only Word I had was 'Wow!'"