Charter Arms Bulldog Black Passivate

[ventana]

Greetings,

I noticed that Charter Arms is offerring a Bulldog revolver having a balck passivated surface finish.

Any idea if the steel used to manufacture this model is carbon steel or stainless which is subsequently passivated black?

I realize that most stainless alloys naturally form passivated surfaces layers but was wondering if Charter Arms somewhow reduces the chromium surface oxide layer on stainless to produce a black surface layer.

Thank you for your attention.