1897 Project No. 1

[browningautorifle]

I think they might be stress lines from the original forging. When the metal was white and degreased, they lightly rusted within 15 minutes after my final rinse.

I wonder...if they might be dissimilar metal? Thus the rust and the definite line? We used to see those in '94 Winchester receivers too when they were worn to the white. Older ones of course...just exactly like what you show.