Quote Originally Posted by scmcgeorge View Post
JB and others: What were the original finishes applied to M1903 rear sight components up through , say 1920? TIA Steve McGeorge
IIRC,
Color case-hardening is correct for RIA leaf sights. I can't locate the source but, I seem to recall that being right.

*Yes, this thread is a little dated; just hope this might still help.