with what I read to check for correct spine you use field points with and without fletcheing, make very small adjustments to your rest and or knock point to see if you can get the two to hit the same if you cannot your spine could be the cause, this is what I used to set mine up
http://www.willowcreekarchery.com/Ea...ning_guide.pdf it worked good for me hope it helps. when I did mine I did the bare shaft test got them to hit good so I thought my BH should hit real good to but they did not they where about 4 to 6 inches high so I made very small adjustments to the rest and the two met in the same hole the bare shaft test will get you close to do the BH tuning.