The way I look at a "mouse gun" is it is better than nothing. I was once told by a OHP that if he was relying on a mouse gun he was going to be on the ground with the perp and that there are a few holes in the head for the bullet to find its way through. I am not an expert on training or human targets/perps but I have hunted more than enough to know that an animal doesn't always know when to die--and we are animals too.