Razor, the AMO length of a bow is 3" longer than the string which will brace the bow the proper distance. Therefore, measuring along the belly of the bow to determine the bow's length may or may not give you the AMO length. Long bow or recurve, the proper string is 3" shorter (loop-to-loop) than the AMO length of the bow. Obviously it is entirely possible for two bows of different overall length to need the same string length in order to be properly braced and those two bows would be the same AMO length. Why they had to create this confusion is beyond me!