Target mediums come, in some cases, close to simulating an animal and in others don't even come close.
As FLHunter described KE is a unit of measurement and penitration a different measurement. Can 1 be used to describe to other? It serves as a guideline but just plugging in the information into a formula isn't going to work in my humble opinion.

The bottom line is what are you going to be hunting?
Does to bow have enough draw weight(standard by most states, 40 pounds for Deer in Ohio) to launch an arrow and broadhead(types and minimum broadhead designs are also governed by most states 3/4 inch in Ohio) to cleanly kill game animal X?

The numbers serve a point but keep in mind the shot is what counts.
Does a recurve at 40 pounds shooting a 3/4 inch broadhead at about 160-180 feet per secound develop enough KE to kill a Deer? The state of Ohio says so. Is it enough for most folks?

I am a firm believer that the shot is the most important thing and if your equiptment is set-up and tuned to group your hunting broadheads, You make a quality shot, The Deer will be a trophy for you. End of Story!
You have a good set-up and hit the point of the shoulder blade, the arrow bounces out, 5 inches back and complete pass through. Do I have enough KE?
IF my only experiance was the first shot the obvious answer is No I Don't!


There are a number of guys who believe the numbers above everything else, and to them I say Good Luck this year. Me I have a hunting set-up and it works.

Greg

"Getting close to the game is the joy of Bowhunting for me, the harvest is a bonus."

Live 15 ft Python after eating a small Antelope!