The Thunderheads do seem to be amoung a fairly small number of fixed heads that are simply but efficiently designed for a minimum of friction on pass through and a tip that is no larger than necessary for starting the penetration. I started my grandson on my extras when I went to expandables and he has had very good luck with them. I see a few others I think would be as good but I am not one to do a lot of expermenting. Heck, I shot aluminum arrows, feathers and fingers until five years ago.