Are you talking about broadhead equiped arrows , fishtailing downrange , if so make sure you have enough stearing in the back of the arrow . I use 5 inch feathers on an offset when shooting fixed broadheads and my arrow flight is much improved over when I use to use 4 inch feathers , some even use heilical .If your feild tiped arrows do it allso , Id check for vane contact and that is not the problem , then time the rest to drop at the last posable moment before contact is posable .