lower nock more till the shafts fly straight, then raise it back up a 16th then 1/8th trying some shots with broadheads from each--> I'll look for flight problems and if you can't have someone listen for the most sound... 2nd now you tune the fletch,, you want that one fletch that strikes into the riser to slice right through the bottom inside corner of your shelf and that it.
this is fine tuning and once locked in that bow will be perfect,,, when done you can fletch with 3 4" feathers for the flattest shot....
also when bareshaft tuning try canting your bow at different angles to see how much better or worse the bare shaft will fly,,, i learned I was canting too much..