What is the purpose of the ribs on a Brenneke slug?
The distinctive Brenneke ribs are not, as is often thought, designed to create spin. Rather, they allow all Brenneke slugs (with the exception of the three-inch Gold Magnum and the all-brass Super Sabot, designed for rifled barrels only) to be used with any shotgun choke. As the slug passes through the three constricted areas inside a shotgun barrel (forcing cone, bore and choke), the ribs compress, allowing the slug to pass through these areas with no damage to the barrel. Somewhat better accuracy can be obtained, however, using a more open choke such as Improved Cylinder.
