Starting to finish

I'm at that point where I actually need to finish my Uzi.  I'm going to start with the bolt, because it's the easiest thing to finish.  As much as I like the machined look, this is an Uzi, and Uzi parts shouldn't be bright and shiny.  I could have all my parts parkerized like the originals, but I don't want to deal with shipping and the cost.  Fortunately, there is another way(and it's really easy).

For the bolt, I'm going to use Precision Tool Black( https://precisionbrand.com/product-category/tool-black/ ).  It's a blackening compound for ferrous metals, and it's super easy to use.  Just wet the metal with it, and almost instantly it turns black.  Here's the bolt, about half way covered(picture taken with my potato camera in poor lighting by the sink).

The Tool Black can't compete with industrial black oxide coatings for durability and you'll still need to keep things oiled to prevent rust, but it also doesn't require any special equipment and it goes on at room temperature.  It's literally wipe on, wait a few seconds, and rinse off with water.  I generally use a chunk of scotch-brite pad as an applicator, though you can just dunk your parts in it too.  A little goes a long way, and you could get several whole guns out of a pint bottle.  After coating the parts, a brownish-black film develops that I buff off with dry paper towels.  The rougher the surface, the blacker it gets so sandblasted parts come out very black, and polished/smooth parts tend to be a very dark gray.  Here's how my bolt looked after being treated: