Outside PB hinge knockles flattened

[DFHicks]

I noticed this on Ed Wenger's great rifle posted here recently.  I have also seen it in pictures of originals.  Why is this done? The reason may be simple but it just isn't obvious to me.  I'm working on a practice mock-up of a curved hinge now.  Are the flattened ends related to this type of hinge?
Thanks,
Greg

[Eric Kettenburg]

Captures the hinge pin and also allows better flow of the raised hinge portion into the stock.

It is best to cut the hinge pin slightly short, then gently hammer the ends down to the point desired (carefully) so only a small amount of filing/polishing for cleanup will be needed; no need for a lot of material removal.

[rich pierce]

Also one less protruding edge to grab onto stuff.

[DFHicks]

Thanks to both of you for the information.  I am trying to learn how to make a patchbox for the rifle I'm working on.  This is something to do on my practice pieces.

Greg