Yes thats an easy fix for someone that knows what they are doing.. Telling someone to sand on there shaft without knowing if they have the proper equipment of even the proper know how is a quick way for them to ruin their shaft. Expecialy with something as corse as 400 grit. Its pritty easy to make your shaft nonconcentric when sanding by hand. You should try to reburnish you shaft first with a undyed piece of leather or a brown paper sack. Just rub it up and down on the shaft and see if you get the desired feel. If that does not work I would suggest taking it to your local cue repairman and having your cue resealed and waxed..