Hello I have a bar that is worn, the groove seems to have become wider then it should be. The chain rocks from side to side. Is there any way to fix this ?
Yup... and once you close the rails, you should make sure to grind 'em square again as well if it's very worn. Bailey's sells a tool for that too, or depending on the tools you have you may be able to just do it on your own. Of course, if the bar isn't that big, your best bet might be just to grab one of the bar and chain specials and start with new. Consider a new drive sprocket (cheap) while you're at it.
Search the chainsaw forum, you'll find lots of posts.