From Lilja's info referenced on page 2 of this thread.
Another factor in surface finish has to do with its smoothness. While it is very desirable to have a finish running parallel to the rifling, the finish can be too smooth.
In our extensive testing we found that a lapped barrel could be made too smooth and that these super smooth barrels would foul more than our conventionally
lapped barrels. We have drawn an analogy between these “too smooth” barrels to racing slicks on race cars. These tires have no tread so they can get better
traction (or more friction) on the asphalt or concrete surface. It seems as though a similar situation results between a bullet and barrel if the finish is too smooth.
But in this case, the result is increased fouling, not increased performance.
