Buy Hornady Subsonic Ammunition 300 AAC Blackout 190 Grain Sub-X FTX Box of 20. Hornady 300 Blackout Subsonic Ammunition is designed for accuracy and performance below the speed of sound. The 190 grain 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 hollow-point cavity to help it expand reliably at low velocities. Performance of the 300 Blackout Subsonic load meets or exceeds FBI Protocol terminal ballistic test requirements.

Other features:

• Impact velocities of 960 to 1,020 fps into ballistic gelatin, providing 16-18” penetration and 90%+ weight retention.

• Designed to expand at velocities down to 900 fps.

• Loaded with unique powders optimized for subsonic use, the low flash signature is ideal for both suppressed and unsuppressed performance.

• Bullets feature a cannelure for a positive case crimp for use in semi-autos.

• Designed specifically to fit, feed, and function in a variety of firearms including gas system guns.