ORIGINAL: BGfisher
If you do a little math you'll find that rated IBO speed is at 30", 70# and 350 grain arrow (nothing on the string. Your figures above would be valid. However, if you divide 325 grins by 65# you come up with 5 gr/lb. Therefore no adjustment should be necessary for the difference in arrow weight/lbs determination.
Thanks that was the info I was looking for. It made sence to me that there would not be a loss if I was shooting 5 grs/per pound.
Thanks again
Mike