Shotgun slug

A modern shotgun slug is a heavy lead, copper-covered lead or other material (like steel or wax) projectile, with or without a plastic tip, that may have what appears to be rifling, but these are special cuts in the slug to let it deform when passing through a tight choke. Slugs are intended for use in a shotgun and often used for hunting large game. 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 choked smoothbore barrel; they must be self-stabilizing in the absence of rifling.

Earlier types of slugs were also used in 4 bore guns intended for hunting dangerous African game in the 19th Century. Such 4 bore guns were produced in both rifled and non-rifled versions. Similarly, modern shotguns have been produced with rifled barrels, or rifled choke tubes, and slugs designed to be fired from them use spin stabilization. As these specialized shotguns are far more accurate than a smoothbore gun, they also usually have a mount for an optical sight, such as a scope. Many of these slugs are saboted sub-caliber projectiles, resulting in greatly improved external ballistics performance.