If I remember right Dr. Ashby tested two different hardness Grizzlies originally. A 44 and an over 50. what is the hardness of these new ones. I may need to get a KME system. Also, if my memory serves me, his original was test one using a modified 190 grain head, 7/8", were any full width heads ever tested. I have always been a little confused by this since the ole Deadhead tested almost as well. I am not so sure that the last newer Grizzlies we got, need to be narrower to penetrate. My wife got a pass through with a 38 pound bow and a super blood trail. I should have taken pictures, but I had no camera. After two seasons of resharpening they are 1&1/16" wide. The hole was bigger than the width of the head, I kind of like the narrower profile for short arrows and light bows.