[joetapley]

No matter how big the group it always has a centre.
Suggest setting the button spring at around 50% compression.
Put the sight pin so it lines up with the string and centre of limbs.
Shoot with the visual image of the string running through the centre of the pin - say at 30 metres
If the arrow group is to the right of target centre screw button out (arrow pile moves away from bow)
If the arrow group is to the left of target centre screw button in.
Aim is to get the arrow spread centred on the middle of the target.
When done above shoot normally and move pin position until arrow spread is again centred on the target.

Nocking point position less important- set at 1/4"-3/8" above square and for the time being forget it.