Nice Job Arthur and right on the money. Though it is generally accepted that the IBO "rule" is a 70 lb draw weight, 30 inch draw length shooting a 350 grain arrow there is still ways "around the rule" to get a bit more speed. For example, I have heard that some manufacturers would take a 31 inch draw length bow and just draw it back to 30 inches (more energy stored than a true 30 inch draw bow) and thus arrive at their version of the IBO speed rating.