Wish I could help, I always thought Titanium was its own finish like Stainless. Look forward to learning more on the subject.
So what have you tried so far? Any gun cleaning products? Bronze wool & oil? Brass brush?I would like to know the answer to that one myself. I have a Taurus Model 415T and have the same problem.
I use these on stainless steel revolvers, and they work very well. Not for blued finishes.Titanium is titanium if memory serves me correctly................
They sell cloths that will remove the carbon like these Birchwood Casey Lead Remover & Polishing Cloth
just don't rub real hard, start very small in a hidden area.......................
It definitely has that slightly rough bead-blasted surface texture, but then I think it has some kind of dull slightly greenish-grey finish applied over the bead blasting. I found info on the 'net about an anti-corrosion and wear resistant finish called Tiodizing that is similar to anodizing for titanium, and it looks a lot like the finish on the 617TiMy guess is that it is a bead blasted finish and that aggressive or abrasive cleaning will polish that finish off and leave it shiny in that spot.