It would depend on your broadhead and distance. KE is calculated at peak speed. The further out the less there is. Cut to tip, Fixed or mechanical require different KE. Because of all the variables I'd give you an answer of "Depends". If I was going with a fixed I'd say give me 50 for a passthrough at out to 30. For a mechanical, give me 60. Then again, it all depends on broadhead diameter.