Ok, so this is not a black gun. It is a receiver to a fine shotgun, engraved by Firmo and his daughter Francesca Fracassi.

This fine engraving is all, 100% hand done. It takes hundreds of hours to create something like this, with the depth of field, shadowing, motion in the scene and stunning detail. The style of engraving is called "bulino". It is made up with nearly microscopic, varying dots and lines with an assortment of different hand graves. This type of artistry is fascinating to me. I would love to own a shotgun engraved like this by Francesca. I believe something like this is now selling for over $500,000, and there is a long waiting list.
Here is another example of their work: