The 49ers made it a point this offseason to improve their special teams, particularly their kickoff-coverage unit.But six games into the 2013 season, one special teams unit has been consistently mediocre – the punt-return team.The 49ers are tied for 18th in the NFL, averaging just 7.1 yards per return. And punt returner Kyle Williams has twice as many fair catches (16) as returns (8).This week, 49ers head coach Jim Harbaugh said Williams actually has been good in the role and has made wise decisions."Those fair catches aren't all on Kyle," Harbaugh told Cam Inman of the Bay Area News Group. "He does a good job of knowing whether to fair catch or return."Many of the fair catches, said Harbaugh, are a result of the 49ers being unable to consistently block the punting team's gunners. Williams, too, said the situations have called for him to make fair catches rather than risk crucial mistakes."They're kicking it short and putting it in a spot where gunners are able to make a play on me and force a fair catch," Williams told Inman. But it's possible that as the season progresses, the 49ers could make a switch at punt returner to add a spark to their return game and get better...