Empirical research points out that most .177 pellets indeed loose accuracy when the range is extended past 60M and past 80M they start to become hopeless. There was a Dutch guy in the old BSAOG who had a BSA Lonestar with long .177 barrel and he tried every pellet available with different speeds + at least two different barrels and the best he could manage was about 4" group at 100M. On the other hand .25 JSB Kings tend to fly in straight ARC to the target at 100M and can easily achieve sub 1" groups with right pellets. Howabout some .25 modelling as well? Ideal twist rates with today's pellets would also be of interest.
Deep and long rifling marks will affect the spin damping and, because they will be at the same angle as the rifling, they will try to keep the ratio between the spin rate and the forward velocity at a constant value. How well they succeed may be debatable. It could also be that the pellets being used are better behaved due to their basic design. Short, heavy pellets will tend to be the worst.
Semi-related....what are your thoughts on LESS rifling marks imparted upon a pellet improving the effects of wind deflecting. (Ie reduced deflection since there's less "fins" for the wind to catch)Think polygonal rifling, or shallow rifling.