Al
You diffinately have to experiment. I found Ash works best for me. Half the shafts from a board come out right at my spine and I leave alone for practice rabbit arrows and what not. The ones that come out spine heavy I taper sand for hunting shafts. You wont believe how easy 10lbs of spine comes off just using sandpaper wrapped around the shaft and your hand (with glove it does get warm). I tried some leapard wood and it spined way to heavey for me around the 100lb area. By the time I sanded to my spine they were knitting needles.