12Gauge

12 gauge is a common shotgun gauge that refers to the size of the bore and the shells it chambers. The gauge system is based on the weight of equal-sized lead balls that would make up one pound; for a 12 gauge, twelve such balls would weigh about one pound. The nominal bore diameter is about 0.729 inches (18.5 mm). Shells for 12 gauge most often come in lengths of 2 3/4 inches, 3 inches, or 3 1/2 inches, with the length affecting payload and recoil.

Shot loads are described by weight and shot type. Typical hunting rounds include birdshot, buckshot, and slug loads. Birdshot uses small pellets in weights around 7/8 to 1 1/4 ounces, with pellet sizes ranging from about #9 to #4 depending on game. Buckshot uses larger pellets such as 00 or 0, and slug loads are solid projectiles. The choice of load influences patterns, range, and penetration, and recoil varies with load, barrel length, and firearm design. 12 gauge firearms are used for waterfowl and upland game, turkey hunting, target shooting, and, in some regions, home defense.

Historically, the 12 gauge gained widespread popularity in the 19th and 20th centuries due to its versatile loading options and broad availability. Modern 12 gauge shotguns come in various action types, including pump, semi-automatic, and break-action, and can chamber different shell lengths within their design. Safety and legal compliance are essential considerations, with requirements varying by country and region.