Krisken there are too many variables to come to an equation that would determine a specific penetration on a specific animal. Somewhere in the vastness of my multi-gig hard drive, I have a table that identifies a range of Kinetic Energies recommended to take a specific animal. But that is as close as one could come.

They do not say that these are the only KE factors that would work, only that they are recommended values. I try to stay within these values and I' d confidently tackle a griz with my 60 ft-lbs of KE in a heartbeat.

In my mind, I think the only way to be sure is to test each setup in a hunting situation which in itself is full of incalculable variables.