Looking good so far, Nitro.

I'd like to see a group comprised of 3 lefts and 3 rights. They'll only be 3 shot groups from each barrel, but will show better how the barrels and loads are actually doing.

With a 6 shot group, you'll be able to see how it regulates with that load by measuring the distance between the each barrel's group centre, compared to the measurement of each barrel's axis to each other.

Even coming together into a single group at 50yards is not bad. At 100yards, the group centres will only be an inch or so apart - probably easily useable to a good 150yards - depending on the ammo's capability.

That is a good looking gun.