Bottom line....spine is just another tool to use in shooting as consistently and as accurately as possible, and in making arrows that have generally the same flight characteristics. My access to quality wood here in Alaska is somewhat limited, and my motivation was, when making my shafts, to find a way to keep quality consistent and to use another gauge other than just weight and diameter. Asking how others measured spine was not a big deal I thought.... seems like nobody on this forum pays attention to it, and thats fine, I won't ask for advice again.