Best solution for re-blueing part of my remmy bolt

[BigBrother]

Really minor cosmetic question here, but my Remmy bolt from a 700P has some minor finish worn off it. It's so small, I just took a permanent marker to it, but it didn't stick.

What solution or product could I use to darken it back up and get it to match the original finish? I've seen some things on Midway but wanted your opinions.

Thanks!

 

[Bioregulator]

Re: Best solution for re-blueing part of my remmy bolt

Birchwood Casey's "Perma Blue" has worked good for me. Touched up an SKS that had significant wear on it, and this product took care of it real nice. The finish holds up very well and is permanent. For touch-ups, simply dip a cotton swab into the solution, and place a drop of it on the metal (degreased). After a couple of minutes, you'll notice the metal change color.
There's another one called "Super Blue", which allegedly gives the metal a deeper black color.