I used the Wasp SST several years ago and killed several deer with them with good results. However, I quit when I shot a good buck that was quartering away and the opening of the broadhead made the arrow kick out to the side.It lost all the energy needed for penetrationresulting in an injured deer that would have been dead with a fixed blade head.Impact location was perfect. Since then I have gone back to the Muzzy 100 and have no reason to look at any other head. I have killed a lot of game with them and never had any problems period. I'll never get bored with something that works. If you are set on trying a mechanical I would definitely stay away from any head that folds open in the manner of the SST. Good luck.