Yeah, it appears I nailed the consistency portion of the tune. However, if I understand the physics correctly (feel free to correct me, as I'm still learning a lot about this extremely variable and interactive process of Impact tuning), you can have two very different harmonic vibration conditions, each of which can produce the same great velocity consistency, but due to the differences in barrel oscillations, one can be noticeably better in group size than the other. This is why accuracy and tight groups are not solely dependent on a given velocity, no matter how consistent.
However, with these group sizes, I don't think it's far from about as good as it will get. If you consider a 0.5" group at 50 yards the 1-MOA standard, which the Impact is know to have the ability to easily exceed, then you reduce my group sizes a little by removing my lower than competition-level holding skill and trigger control, I think even the 10-shot group would be sub-half inch. For now, it's time to shoot this thing and see how she holds over normal use.
I think I'm going to follow a slightly different sequence of operation when I tune mine. Plus a little more testing documentation, vs just good results documentation.
If you're a quantitative technician-type personality like I am, this tuning stuff is almost as much fun and rewarding as the general shooting! A rifle to tune, a few tins of pellets, a CF bottle of air to tether to on the shooting table, a LabRadar, and some clean target sheets. All the makings of some quality time (HOURS of it) in my own little corner of the world.
The below pictures actually show the setup from my first round of tuning. For the data collected this last round and published above, I didn't use the machine rest, but shot off the bipod and rear bag, so the results would be more true to my real-world conditions.