I'm certainly no expert here, but did you do a powder test to check for contact with your rest? Make sure all your nocks on the arrows are aligned the same way. Pay particular attention to your anchor point and follow-through. Are you anchoring in the same place EVERY time? Are you concentrating on follow-through? What grain of tips are you using? When I am inattentive to my shooting I can spray arrows with the best (or worst) of them. I find that when I am totally concentrating on form etc. I don't have that problem.