Federal Premium Hydra-Shok has proven itself for self-defense since 1989. Hydra-Shok Deep builds off the time-tested platform with design improvements that better meet modern performance measurements. The bullet features a more robust center post and a core design that penetrate to optimal depths through the barriers most commonly encountered in self-defense situations. Features: Hits optimum penetration depths through barriers encountered in self-defense situations Iconic center post design has been improved for better, more consistent expansion Specially formulated propellant Extremely reliable primer Penetrates 15 inches in bare ballistics gel-the ideal depth according to modern FBI standards