I never go finer than 320 anymore. You can blend the surface with maroon scotchbrite, I think that looks good. I prefer it over sandpaper. If you are going to brown it don't go to fine. The brown won't work as well and the surface you so lovingly polished to a mirror shine will be etched away anyway. For barrels I now draw-file with a very large file and then blend with the scotchbrite pads, that's it. For furniture I have been filing off all evidence of casting. I then polish in the most expeditious way I can, and then lightly sand blast. Then brown. The brown works really well on the blasted surface. It come out a satin egg shell texture, not super rough.
You posted while I was typing. I think Jim uses scotchbrite with that. Shoot him an E-mail and see. Katherine can probably answer if he is busy.