I should probably know this but what does the 6.5 stamped for each barrel just ahead of the lump?

On my what I think is a 6REE it is stamped the same way with a 7.

Also, the quality of the engraving on the rib doesn't seem to be nearly the quality of mine.


The world cries out for such: he is needed & needed badly- the man who can carry a message to Garcia