Octagon barrels are typically polished lengthwise.
Round barrels are typically rough polished with emery cloth strips while being spun in a lathe.
If a final mirror finish is desired, it doesn't matter which way you polish, because you have to polish every which way to get all the progressively finer scratches out left by the last grade of paper you used.
You change directions each time you change to a finer grit.
Then there will be no scratches left to show when you start free handing it with the cotton buffing wheels & finer & finer grades of polish.
For a typical factory finish on a .22 or something, you can probably stop with 240 or 320 grit black wet or Dry emery paper strips applied "shoe shine" fashion.
Best advice is just look at a firearm with the type of finish polish you hope to duplicate and stop changing to finer grits when it looks like that.
Hot bluing does not "cover" anything up, so what you got is what you get when it is blued.
rc