I used them last year and they will be in my quiver this year. They fly awesome the same as my field tips and i did not have to change my sights at all. As for the penatration my buddy and my self blew right through are deer and we are shooting 70# my daughter shot her buck with a 42# hoyt and the tip of the broadhead was just sticking out of the oppisite side shoulder..They do make a whistle when shot but none of the three bucks shot ever flinched.. Walt