I had the same thing happen to my Muzzy 4 blades several years ago. Broke off the tip, just at the base of the treads on 2 heads after going thru a target and killing a tree. I was living in Atlanta, near Muzzy's offices. Stopped by and showed them the heads. They wanted to keep them to investigate the problem. Gave me a tour, including a live drum test. Then gave me a new package of heads. Great people, great head. Send them back to Muzzy with an explaination of what happened.