Highly unscientific. Different draw weights and all that. BUT, let the games begin.[8D][8D][8D] I think I would get a couple different materials and shoot each several times coming up with some sort of average. Like Arthur says, ballistic gel would be the ticket. No need for a whole bunch of shots and determining if it was equal, it would be.There are recipes for making it, but it's just too involved and you'd need large refrigerator space.