One other question I would have for you is, What distance are you shooting when the arrow impacts begin to open up? If they are opening up at 10 - 20 yards, then there is a form problem or you are jerking the release.... If the are opening up at 40 - 50 yards, then it is a stability ( strength )and focusing problem. It is a lot easier to " miss " from 40 or 50 uards than it is from 10 yards. At 10 yards you should just about be able to group in a pie plate even without sights.... that is not meant literally, but rather in a figureative sense..... and how long have you been shooting and how much do you practice?

MET