When an arrow enters and animal it decreases in speed, it doesn't immediately stop unless the arrow lodges in heavy bone. Even if a low poundage archer doesn't get a pass through the arrow still decreases speed rather than just stopping. This leads me to believe that when this happens this product won't perform as advertised on regular good shots, because on the site they advertise it as working when the arrow comes to a complete stop like what happens in a target. However, I do believe it will make a difference when contacting heavy bone. How much of a difference? In my opinion not much, I believe all it may do is shatter the bone, but not much else. For it to work properly it seems the arrow must come to an abrupt stop, like what would happen when contacting heavy bone, once it comes to that stop the weight slams forward causing secondary force which I believe will shatter the bone, but don't believe will propel the arrow any further into the game animal. This is all opinion though.

I would definitely like to test one out to see if my opinions are all unfounded though, I have been wrong before and this may be no different. I just don't see spending 30 bucks to test one though.