Saboted slugs have the same damage profile as Rifled Slug, though with +1 PEN.
Rifled shotguns work better with slugs which are encased in a plastic sabot, which spins through the barrel and disintegrates upon exiting it. Saboted slugs approach the accuracy of a low-calibre rifle with the muzzle energy of a .308 bullet, though much greater stopping power. The projectile itself can be constructed from harder materials such as copper, bronze or steel.