Just for the sake of curiosity...I've been cleaning and dressing a lot of old bars this week (70 or so...) and find a lot of variation in the depth of the grooves, not all of which is a result of wear of the rails.
Bars are branded/made by Oregon, Windsor, McCulloch, Homelite, Mall, Sandvik, even a few David Bradley.
Many older, solid bars seem to have a very shallow groove even for bars that had not had a lot of use.
More modern, primarily sprocket nose bar seem to have a much deeper groove, some almost 1/2".
A few show signs of excessive wear of the rails...
This one is so worn around the nose that the drivers no longer seat in the groove. There was no hardfacing on the bars with the three holes at the tip.
This one was run for a long time without being flipped, rails are worn on the bottom but fine on the top.
And some you can see the extreme wear close to the saw where they cut a lot of smaller diameter wood right against the saw.
These two started out the same length. One has a lot of wear close to the saw, the other was evidently cut down and the groove reground...I cannot come up with an explanation as to why they would have done that.
You can see that the hardfacing has been repaired on the bar on the bottom, but the entire tip has been ground away and regrooved on the bar on top.
Mark
