39 yds for us low ke folks is a long poke. Congrats to your wife. On the long shot, did the broadhead happen to hit the opposite shoulder or leg bone? Or did the arrow just run out gas before acheiving a passthru?

I used 3 blade muzzys with great luck on hogs and deerwhen I was at 37lbs of kinetic energy. I think I'm up to 48lbs now and I'm still using the muzzys. (don't see a reason to change)

I have some info on my website like that. There are no "hard and fast" rules but the more info one has the better and more informed his or her choice will be.
www.broadheadtests.com

Doegirl, unfortunately the deer had enough time from the time my wife released until the arrow got there to take a step and turn away from us.The arrow entered the left ham and penetrated fairly well considering it hit the leg bone pretty solid. Luckily the broadhead cut the femoral and he didnt go 40 yards max. Thats one reason why I always preach use the sharpest broadhead you can. In all actuality she shouldnt have shot that far but thats my fault, I ranged it and thought to myself 39 yards is a chip shot, not realizing how slow her bow is andnot taking into conisderation that the deer could take a step or two by the time her arrow got there. Not taking anything away from her, she is a heck of a shot at fourty.

[/align]
[blockquote]
[quote]ORIGINAL: Doegirl75

Actually , all expandable heads require little measurable amount of K.E. gain (in percentage terms)to actuate.
TheextraK.E. that is often spoken of (in referring to expandables) is due to the cutting area being larger and therefore requiring more energy for same penetration.

In testing we found that a jackknife style expandable needed 3# more K.E. for total actuation in comparison to a fixed head of the same size.
[/blockquote]

[/align]
[blockquote]
I would agree and like to add that the list I put up is for worst case scenario which refers to a scapula strike which is the most common area impacted which occurs in loss of the whitetail.
The list is based on testing which was done on 2 1/2 yr. old whitetails.
The weights , distances reflect the point at which an arrow can still clear 10" of penetration.
(10" is the second lung on the off shoulder side)
As was stated on the chart......best performance.
Best doesn't concern itself with what will do some times
[/blockquote]