Chuck,
.0042 is perha[s a little too fast for a finish cut with a sharply point tip on the cutter. As Pierre said, if you radius the tip of the cutter, you will usually get a better finish. They also make carbide inserts with radiused instead of pointed tips. Also, after finishing a pass, or at least the final pass, you should always back the cutter out before cranking the carriage back to the starting position.
For use on steel, I keep on hand a roll of 2" or so wide 220 grit sand paper. And a 10" or so long piece always torn off and available on the ready service shelf behind me. After the final cut, I hold the strip in the right hand, drop it over the part, catch the other end with the left hand and pull it around the part and walk it up and down the length two or three times to polish. Then wipe off the part and check the diameter.
The only real complaint that I have ever had with the Atlas feed rates is that the cross feed is about twice as fast as the longitudinal feed. Too fast for most milling.
The phenomena where a second pass removes just a little metal is I guess just something that happens. You can minimize it by keeping all three gibs properly adjusted.
Robert D.