Gunmetal refers to the metal components of a firearm, particularly the barrel and receiver, that are made from durable, corrosion-resistant materials. Traditionally, gunmetal was a specific type of bronze or brass alloy used in the production of firearms and other weaponry. However, in modern terms, the word "gunmetal" often refers to the overall finish or appearance of a firearm's metal parts, which are typically treated or coated to prevent rust and wear while providing a sleek, attractive look.

The term is commonly associated with the grayish-blue or darker hue that is typically seen on the metal parts of firearms, particularly in the context of older guns. This finish, achieved through processes like bluing, gives firearms a distinctive, weathered appearance while providing a layer of protection against corrosion.

In some cases, the term "gunmetal" is still used to describe the metal alloy used in certain parts of a firearm or other equipment, although modern firearms are typically made from steel, aluminum, or synthetic materials for enhanced strength, weight reduction, and durability. Nevertheless, the historical association of gunmetal with high-quality firearm components remains strong in hunting and shooting circles.