A kinetic energy penetrator for use in small caliber ammunition, which penetrator can utilize composite material small sabots. A large shear area in the sabot having a small number of decreasingly sized buttress grooves, mate to the penetrator shaft making use of composite material sabots feasible. Lightening of the penetrator through substitution of composite material sabots results in greater velocity with higher kinetic energy on lethal impact. The fewer grooves aerodynamically lessen drag and likewise tend to boost velocity plus lethal impact.