The Hornady .300 Blackout 190 Grain SUB-X is designed for accuracy and performance below the speed of sound. The new 190 gr Sub-X (Subsonic - eXpanding) bullet features a lead core. Long grooves in its gilding metal jacket combine with the bullet's flat profile and the patented Flex Tip insert within its hollowpoint cavity to help it expand reliably at low velocities. Performance of the Hornady 300 Blackout Subsonic load meets or exceeds FBI Protocol terminal ballistic test requirements.