question about Ballistic Knives
 

I don't know if this is the correct area to post this but, I have a question about "Ballistic Knives". I already know that their highly illegal and I was curious if anyone has one in their possesion w/o the coil spring? A

nd I'd just like to know some of the facts on "Ballistic Knives". Such as how fast they can travel in FPS (Feet Per Second) and how accurate they are up to what distance?

I reason I'm asking this is because I can't find any inforrmation (on the web or in books) on them, and I was wondering if anyone on this forum could help clear up some of the questions that I have?