Hopefully your friend didn't already make a bunch of these because this is a horrible idea. It would not make a marginal shot into a kill shot, unless you count gangrene as a kill.
How old are these kids? 12? Good for you guys trying to be ambitious, but this is a terrible idea for deer hunting. But, will it work on humans?
By the way, if I wanted this product, I'd just take an insert I already have, put a hole in the bottom, put a wire in it and secure it. This product belongs to the hall of shame.
I hope like hell this never sells. This has to be one of the dumbest ideas I've seen to date for deer hunting. Sorry, but I'm with Bruce and other on this one. This has no place in the woods, none at all. We are all trying for a HUMANE and ETHICAL kill on the game we hunt. This is neither.
