Advantages as I see them for the 6.8SPC is a low recoiling hunting round you could use in your AR for Whitetail legally on public land. It's intended purpose from the get go was a more effective man stopper in an intermdiate range. So the 300yard accuracy thing although IMHO is overblown is not out of the question. I'm sure that it would get the job done beyond that. Funny how we want to get closer to the 7.62x39 round, or somewhere in the middle. I'm not opposed to the 6.5 Grendel either will get the job done better than the 5.56. Sorry mini rant! I'd like to see both cartridges take off.