320 gives me the finish I need for my processes., keep in mind I don't do oil finishes.I see you stop at 320 grit. What happens if you put in some extra time and go on to 500 and then 1000 or maybe even 1500-2000.
Been years since I did anything but I always did this and got a really slick finish. Of course that was a while ago when staining, sanding and then adding numerous single coats if urethane and sanding was the accepted way to finish wood. Lot of elbow grease but immaculate finishes if you put the time in.