Federal Premium 40 S&W Ammo 165 Grain Hydra-Shok Deep HP Projectile review offers the following information; This 40 S&W cartridge from Federal’s Hydra-Shok Deep line of ammunition features a 165 grain jacketed hollow point projectile. The bullet offers the distinctive Hydra-Shok center post, which has been made sturdier so it can cause even greater expansion than the trusted brand is well-known for, as well as to permit penetration through a variety of barriers while mitigating negative effects on its devastating terminal performance. Because this bullet consistently penetrates 15 inches of bare ballistic gel, the depth considered optimal by the FBI’s current standards, it is optimal for self-defense in situations where bystander safety is of the utmost importance. This cartridge also offers a reloadable brass casing, which is nickel plated to facilitate feeding and ejection in semi-automatic handguns.