I have several prints and only see freebore as the difference.
Freebore is the big difference, but throat diameter is usually a little larger on the 5.56 spec, as well as slightly looser neck and chamber dimensions. (there are exceptions, "usually" being the key word). The Wylde chamber combines the long freebore (enabling hotter loads, much like Weatherby Magnum chambers) with the tighter throat diameter for better accuracy.
