Joe, That borescope image is fantastic.
I've always wondered why I can't seem to get the grooves of my barrels completely clean as they always appear to be rough and dirty. I've suspected that much of the roughness may be from the manufacturing process where they maybe push through a cutter like a broach that leaves the roughness and only the lands get micro polished. Theoretically, as long as the edges of the lands are crisp and work to spin the bullet, the bullet should never come in contact with the bottom of the grooves. Unless we allow the grooves to fill with crud (which yours are clearly NOT) I suspect we should be OK.
However, if the lands are damaged, galled, or filled with lead or copper; that could certainly affect the trajectory. But I suppose as long as it remains consistent the accuracy might not be affected??
Dunno, but your posts have certainly been enlightening. Thanks Joe.
Now for the true test..........Do they shoot better!??