I agree that centershot makes a hugggggggeeeee difference. I was shooting 5-6 inch groups at 20yards. Then I pulled the biscuit and put it back on, resetting everything. When done, I shot a few arrows. Have 2 arrows split at the nock after that tune. I have 4inch hellical fletched carbon arrows. Getting center made the difference and making sure the biscuit was at a 90 degree angle to the arrow.