The type of materal your bows made from dos'nt matter. The closer the bow is to center shot the more forgivie the spine is. Shoot,boo,river cain materal is more spine forgiveing. Meaning theres a wider range in bow weight these arrows can be shot from. The closer the bow is to center shot this the range in spine is wider still. Meaning a 50, 55 # bow might shoot a arrow spined from say a 40 to 65 # arrow given the materal. Or did I read this question wrong.