I just found the rear sight blade in a much used Model 14 has noticeable fore and aft play; side to side seems relatively tight. For comparison, I checked some other rear sight blades on S&W revolvers. Some have no play, others have minimal play, less than the M14.

What is the best way to correct this if it needs correction? I'm unable to tell by shooting benchrested groups at 25 yards that it affects accuracy so far.