Thae results aren't that earth shattering from purely a penetration point of view. While I do think that all of the tests that are doneto insure the best possible performance is a good thing, I don'tfeel the resultsalways carry over into practical hunting applications. There are so many intangibles when one is shooting at a live animal that it is impossible simulate each one.

For example:

Shooting a two blade head out a well tuned bow producing around 70 ft.lbs of KE andhitting an average sized buck (for this area) of approximately 180 pounds in the meaty shoulder area at 18 yards, I was unable to get a complete pass through even though I didn't encounter bone.

Using the same arrow (manufacturer) with a set up that produced approximately the same KE I was able to get a complete passthrough at forty yards through a 200+ lb buck using a mechanical head. The arrow entered just forward of the right flank and came out the front of his chest.

There are just so many factors that effect penetration everything just doesn't come out "black and white" in each senario. Angles, cross wind, ricochet (internal), movement of the animalat impact, poor release, ect. can all influence how far that arrowwill or will not drive into an animal. There arefew "absolutes" when one is dealing with live game.