If the bow is paper tuned well,you said it is, I would try a lower profile head and see if a more compact fixed head flies better. The Muzzy has a lot of blade surface area, blades are like fletching on the front of the arrow; reduce the blade surface and subsequently reduce the tendency to plane. I would suggest trying a head like the Slick Trick standard or Wasp Boss Bullet and see if they fly better, they do for me.