To find your bow's stored energy (SE) you have to develop your bow's force draw curve. Draw the bow one inch at a time, all the way from brace to wall, and record the weight at each inch. Then you add up all those weights and divide the total (which would be in inch pounds) by 12 to get the stored energy in ft lbs.

Then after you weigh your arrow and shoot through the chrony to get your KE figure, then KE/SE = Efficiency. Multiply that by 100 to get the efficiency percent.

Edited by - Arthur P on 09/10/2002 13:49:01