I hope I'm not stealing this post..
I also find that different species of wood shafts fly better from various bows. eg. Yellow cedar arrows spined at 40# shoot good from my laminated 3 piece wood bow, but not so good from the 40# one piece. And vice versa on other bows. I could shoot 4 different bows using same arrows and maybe only bow will perform well. And changing wood species but same spine will vary between bows. Anyone know why this is exactly.