Olink, I have no idea what program your using, but if that software is telling you that a 550 grain arrow at 255 is going to deliver the same kinetic energy as a 400 grain arrow at 280, their are blowing smoke up your butt. Take your baseball and throw it against your garage door than borrow your wife's bowling ball and throw that at the same door. Now tell me which one has more kinetic energy. The fast baseball with little weight or the slower bowling ball with 10 times the weight. Same same when throwing a javaline, shooting a bow or your favorite bullet.