i have used them and harvested 2 elk, 3 deer, 3 turkeys but i have hit 1 elk on the outside ridge of the shoulder bone and it bounced back and fell to the ground with aluminum tip bent like a hook (the elk gave me the middle hoof and ran off like nothing happened). although i have used swhackers occasionally i do not endorse them because of the background of how they got to market (another story) and i think there are lot of other fixed and mechanical broadheads that will work just as good and probably better.