Thanks to Enzo for sending this our way.
Waffenschmiedin x builds an 1880 Single Action Revolver from a piece of 4140 steel that was heat treated to a rockwell hardness of 27-33. She makes the entire revolver including the screws from this piece of metal. Better yet she filmed the process. It is currently a 13 part series on her YouTube channel. But the 13th episode only shows her cutting the rifling in the barrel. So I suspect there will be more videos later.
Here are some screen captures of her work.

Rifling of her 1880 SA Revolver.

Waffenschmiedin x sanding the wood grips for her revolver

Cylinder after she bored out the chambers
If you are interested in watching the rest of the series go to her YouTube Channel.