Chosen by the FBI as their primary service round, the new Winchester® Supreme Elite Bond PDX1 handgun ammunition exceeds FBI barrier penetration protocol standards and is now available in eight popular handgun calibers. Superior to competitive personal protection loads, the Winchester Supreme Elite Bond PDX1 uses a proprietary bonding process that combines the lead core and the copper jacket into one unit to control expansion and enhances retained weight. The bonding process allows the bullet to penetrate tough barriers and enhance impact velocities and ranges. Six-segment jacket notching facilitates controlled, incremental and desirable expansion at a variety of impact velocities. Bullets expand up to 1.5 times their original diameter for maximum stopping power. The copper alloy jacket is engineered for optimal terminal effect over a wide range of velocities and ranges. Positive gun function and smooth chambering and shell-case ejection are improved by the use of nickel-plated shell casings. 20 rounds per box.