FN America Personal Defense, 5.7X28MM, 30 Grain, Jacketed Hollow Point, 50 Round Box 10700030 FN DFNS is the first 5.7x28mm ammunition perfected for personal protection. The unique 30-grain jacketed hollow point bullet contains a copper-tin powdered core designed to expend energy quickly and efficiently. Protect what matters most with the FN DFNS, tested and perfected for optimum performance in 5.7x28-chambered firearms.