The rifle looks good, barrel looks really heavy and short, not much on flex.
As you know, the tuner attempts to minimize the vertical string of shots.
Try this test on your barrel:
Shoot the rifle without the tuner on, at a target. Shoot 3 rounds and see Point of Impact (POI).
Now, put on the tuner, and twist it out as far as you can on the numbering system.
Shoot at the same Point of Aim (POA) on that very same target.
The POI of your second 3-round group should be at least 1/2" below the first group without the tuner.
If not, you need to put on additional weight to the tuner.
If the rifle shoots to the same POI with and without the tuner, that probably means the tuner will not affect grouping.