Subsonic, 300 Blackout, Subsonic, 190 Grain, Sub-XHornady, Subsonic, 300 Blackout, 190 Grain, Sub X, 20 Round Box 300 Blackout 1,050 Feet per second 190 Grain Sub X 20 Rounds per box Product Description Hornady 300 Blackout Subsonic Ammunition 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