sounds to me like you have bad form, or a bad setup on your bow maybe your drawlenth is to long for ya , i used to hit my arm on my golden eagle and never figured out the problem until i went and bought a mathews outback now the shop told me drawlenth was way to long on the old bow , i was shooting 31 inch arrows now i shoot 28 and a half inch arrows , maybe that is your problem ,,,,,,,i used to drill the bullseye with the old setup to so just because you hold a nice group dont mean its not setup wrong,,, hope that helps