CBM SC: I'm shooting Beman 340 shafts with 125grain Magnus heads and a whisker biscuit. I use 3" feathers in a straight fletch and the fixed heads are hitting inside an inch at 20-25yards. Use the correct spine arrows for the bow. Adjust the rest so that the arrows hit the same verticle line. The whisker biscuit launches a very stabile arrow and you don't need to correct flight much on an arrow thats already going straight. Good luck hunting!