https://gamesartist.co.uk/remington-870/
3D Artist Li Fuhao breaks down the creation of a custom Remington 870 shotgun. In this article, Li discusses reference collection, modelling, UV unwrapping, baking, and walks through the material creation process in detail, covering base color, color variation, and detail rendering for both the wooden stock and metal receiver, before finishing with his rendering approach.
https://www.artstation.com/user-82478198
https://www.artstation.com/artwork/YGDaWX