What does the term "gauge" refer to in firearms?

The term "gauge" specifically refers to the diameter of the bore in shotguns. This measurement is critical as it determines the size of the shot shell that can be used in the firearm. The gauge number is inversely related to the bore diameter; for instance, a 12-gauge shotgun has a larger bore than a 20-gauge shotgun. Understanding gauge is essential for wildlife officers as it affects the type of game that can be hunted as well as safety and regulations regarding firearm use.

In contrast, the length of the barrel, while important for various ballistic reasons, does not define the gauge of a shotgun. The weight of the firearm can influence its handling characteristics but is not related to the gauge measurement. Finally, while the type of ammunition is critical for performance and safety, it is distinct from the concept of gauge as it pertains specifically to the barrel diameter in shotguns.