Steve,
I haven't used it before. Let me know what you think. I have used shag bark, shell bark, and pecan. Pig nut has never shown up at the lumber yard here. I have heard pig nut is more elastic in compresson, but have never had a chance to try it. If your white hickory has that dense waxy luster where you have cut it, it can't be too bad.
I have done OK with shellbark and shagbark for flight bows.
Dan