study this for awhile

http://www.eastonarchery.com/downloa...ning_guide.zip

then maybe try "bare shaft tuneing" , for myself I get better results with that method , allthough I used to swear against it , it seems to work for me now . Start close if you try it 5yards or so and then work your way back . If you are useing lite alluminum arrows you may wreck some .