Funny you mention it, my buddy Frank broke at least 2 off in a Morrell Range Bag target at our club. They were broke at about the point where they were sticking out of the bag......just snapped and barely hanging on.
Just from the force of impact.
I think he broke another one in a 3D target that day as well? I need to call him to refresh my memory but it wasn't pretty.
This was winter and below freezing so maybe the cold played a factor? But in any event I HAVE seen the Maximas literally snap off for no apparent reason.