I’m sure you’ve been just pining to know all about impact fractures and be provided with a somewhat humorous depiction of this occurrence.  So, while surveying, I’ve found a lot of broken projectile points in the field, which are then discarded since they can’t be fashioned into a new point.  Some of the points broke upon impact with the target, still showing how the tool literally fractured into two or more fragments.  Exciting Stuff.