Your feathers are not wearing your riser. The shaft of the arrow is making contact and that is what is causing the wear. Your arrow is too stiff. If you had an old fashioned bow, I would suggest playing with the brace height and tip weight, your modern bow has all sorts of adjustments that I don't have a clue about. Your basic problem is a too stiff arrow, you are going to have to break out the book and see how to adjust the bow. Bill