Foster slug

A modern shotgun slug is a heavy projectile made of lead, copper, or other material and fired from a shotgun. Slugs are designed for hunting large game, self-defense, and other uses. The first effective modern shotgun slug was introduced by Wilhelm Brenneke in 1898, and his design remains in use today. Most shotgun slugs are designed to be fired through a cylinder bore or improved cylinder choke, rifled choke tubes, or fully rifled bores. Slugs differ from round-ball lead projectiles in that they are stabilized in some manner.

In the early development of firearms, smooth-bored barrels were not differentiated to fire either single or multiple projectiles. Single projectiles were used for larger game, though shot could be loaded as needed for small game and birds. As firearms became specialized and differentiated, shotguns were still able to fire round balls though rifled muskets were far more accurate and effective. Modern slugs emerged as a way of improving on the accuracy of round balls. Early slugs were heavier in front than in the rear, similar to a Minié ball to provide aerodynamic stabilization. Rifled barrels, or rifled choke tubes were developed later to provide gyroscopic spin stabilization in place of or in addition to aerodynamic stabilization. Many of these slugs are saboted sub-caliber projectiles, resulting in greatly improved external ballistics performance.

A shotgun slug is typically more massive than a rifle bullet. As an example, one common .30-06 bullet weighs 150 grains (0.34 oz; 9.7 g). The lightest common 12 gauge shotgun slug of 7/8 oz. weighs 383 grains (0.875 oz; 24.8 g). Slugs made of low-density material, such as rubber, are available as less lethal specialty ammunition.

Shotgun slugs are used to hunt medium-large game at short ranges by firing a single large projectile rather than a large number of smaller ones. In many populated areas, hunters are restricted to shotguns even for medium to large game, such as deer, due to concerns about the range of modern rifle bullets. In such cases a slug will provide a longer range than a load of buckshot, which traditionally was used at ranges up to approximately 25 yards (22.8 m), without approaching the range of a rifle.

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