A plastic, cup-shaped, multi-petal sabot housing a sub-caliber projectile for use such as in shotgun cartridges. The sabot engages the rifling of the shotgun barrel and transfers the spin to the projectile. A reinforcement disk is advantageously at least partially embedded in a sabot base and has a central aperture and a plurality of additional apertures. Sabot base material extends through the additional apertures. Advantageously, in its relaxed condition, each sabot petal includes a protrusion from its inboard surface for engaging a projectile ogive. The protrusion and its contact area with the projectile are fractions of the local petal width.