I checked this out a couple years ago to see how it compared to actual chrono tests. Sighted in for 20 yards and using that pin to shoot 40 yards my groups averaged about 16" low. This should indicate a speed of just about 294-295 fps. The bow actually chrono'd at 264. Therefore I deduce that the hart is malarky.

As for Kinetic Energy, the only way to calculate this is to know the mass of the arrow and the speed of that arrow at a given distance. Just from practical experience I've learned that for deer sized game any properly spined arrow for any bow of about 50# is enough to do the job---period. I don't need bone splitting energy because that's not how broadheads do their job.