You've got to remember that the broadhead is designed to glue onto a tapered end of a wood shaft. When you add in the machining tolerances for a threaded insert, and then the machining tolerances on a threaded taper adapter, you've got a lot of possible ganging up of tolerances. Usually just changing to a different threaded adapter will cure the problem. Sometimes you have to change the adapter and the insert. Sometimes it takes a bit of force. I keep a 2X4 block on my table and, when I have one that just won't spin true, Ipush the broadhead against it and try to shove it into alignment. Sometimes it works; sometimes I just save that head for wood shafts.