A shotgun gauge refers to the size of the shotgun's bore, which is determined by the number of lead balls of a specific diameter that equal one pound. For example, a 12-gauge shotgun means that twelve lead balls of that gauge's diameter weigh one pound. Common gauges include 12-gauge, 20-gauge, and 410-bore, with each offering different characteristics in terms of recoil, shot capacity, and suitability for various shooting activities. The gauge system is inversely related to the bore size; a lower gauge number indicates a larger bore. This means that a 10-gauge shotgun has a larger diameter than a 20-gauge. The choice of gauge affects the type of ammunition used and the intended purpose, such as hunting, sport shooting, or home defense.