Centre Shot? Off centre sight?

[Marcus26]

Chances are your sight bar is not vertical. This is easily fixed.
Go to 5m and set your sight at the top of the sight bar. Shoot an arrow into a target. Now move your sight to the bottom of the sight bar and shoot again aiming at the same point. Your arrow should hit a fair way above your last shot and should be in perfect line. If it is not adjust your sight bar left and right till they do.

Once that is done go to 30m. Shoot and asjust your sight till it's hitting X's.
Now go back to 70m and shoot (obviously move your sight down) and you should hit the middle.
If you are going to the right then adjust your centre shot to the left. Should require only a very small movement. Once it's hitting the middle. Check 30m. You may need to do this a few times to get that accurate spot.