What is meant by "gauge" when referring to shotguns?

The term "gauge" when referring to shotguns specifically indicates the number of lead balls of a certain diameter that would equal the total weight of the shotgun's bore in pounds. Essentially, a lower gauge number corresponds to a larger bore diameter, meaning that a 12-gauge shotgun has a larger bore than a 20-gauge shotgun.

This system of measurement originated from the historical method of determining the gauge using lead balls, as it directly relates to the weight and the size of the projectile. Thus, understanding gauge is crucial for selecting the appropriate ammunition and ensuring the compatibility of the shotgun with the shots being used.

Other options do not accurately capture the meaning of gauge in relation to shotguns. For instance, barrel length does not relate to gauge, and the diameter of the barrel, while it might seem connected, is more directly indicated by the specific gauge designation itself rather than a direct measurement. Similarly, the type of ammunition used for a shotgun is distinct from the gauge, which strictly refers to the bore size and its measurement in comparison to lead balls.