I'm shooting spitfire 100 grain heads and have never seen such damage done to the inside of a deer and an exit hole as big as these things make...I have shot thunderhead 125's and then for years and years I was a live and die muzzy bad to the bone guy until a couple years ago when a guy we were guiding for bear shot one with the spitfire 100 and I have never seen such carnage...I started shooting them 3 years ago and have shot 9 deer a bear and 2 yotees and it was complete wreckage on all of them...I wont switch heads until these dont open or fail me for some reason...Hopefully never....There are tons of good heads thats for sure...