Bear in mind that each has it's place. I own rifles in each caliber. Now I can't speak from combat experience (I have none) but I can from a ballistics point of view. I like them all. The 5.56 NATO is a nice flat shooting very accurate round when fired from an accurate rifle. But it really needs 20" of barrel to reach its full potential. I'm not saying they won't do the job, just that 5.56 out of a 14-16" barrel is sub optimum.
That's where the 6.8 SPC comes in. It was conceived to offer excellent ballistics out of 14-16" barrel. And it has good enough terminal ballistics from a 16" barrel to impress Doc. Roberts, and that's enough to impress me. He has my respect.
