The deal is that it is likely more accurate than a 5.56 chambered rifle/carbine, but the degree to which it is more accurate is most likely way above all of our paygrades.
That said, I have a 16" .223 Wylde set up for long distance. I think my Wilson 5.56 is more accurate. Chamber/bore alone isn't going to get you there. Quality of the barrel is as important or importanter. ( yes, I know, but I like that word).