I took some serious extra time this year paper tuning my bow. I bare shaft tune to the point I was getting a near perfect bullet hole. I then began shooting my East Axis 400's w/ 2" blazers and was getting 4" groups at 40 yards. I decided to try my 4" feathered arrows at the same distance and although I still was able to consistently get a 4" grouping, all the feathered arrows were grouping about 6-8" straight to the left. I can not for the life of me figure out why. I could understand up or down based on a weight difference between 2" vanes and 4" feathers ( Although minimal ) I can not come up with a valid reason for directly left by that much. Any ideas anyone?