Quick update. I got the super blue and am surprised by the result. I'm not a gun owner, so the various finishes were unknown to me.
Birchwood Casey Super Blue claims to be "the most black" of their various products. On the other hand, they also say it is for a "mirror finish". When you apply it a few times, rinsing between, it sure does look black, but it looks messy and has to be polished with 4/0 steel wool, and the final result is a shiny, somewhat darker, finish.
A video tutorial I watched last night showed someone using Birchwood Casey Perma Blue, and the end result was truly black, and there was no buffing involved.
If one wants a black finish, which product is actually to be recommended?
Derek