Marc,  while it will temporarily remove the side play, turning
the front rail pins only causes premature wear of the bushing felt,
which results in the side play returning quickly.

How bad is the side play?  I would rather have a little play than
have sticking keys.  Of course, if the side play includes a rattle,
then you'd better rebush.  If you are doing a complete rebuild,
there's no sense in doing a shortcut here: "penny wise, pound foolish",
as they used to say!

David Dewey
(Who's really _cheap_ but learning when not to be!)