The Hornady Subsonic .300 Blackout 190gr Sub-X load (Hornady item no. 80877) is built to stay below the speed of sound while still expanding reliably, so it suits suppressed and unsuppressed rifles alike. The 190-grain Hornady Sub-X bullet has a lead core, and long grooves in its gilding metal jacket combine with a flat profile and a Flex Tip insert in the hollow point to open up at low velocity. Hornady selects the powders for lot-to-lot consistency and a low flash signature. Each box holds 20 rounds, which is enough for a sight-in and a few range sessions with a heavy .300 Blackout bullet.

Key Specifications

• Caliber is .300 Blackout, the 7.62mm AR-15 cartridge that Hornady loads here as a dedicated subsonic round.
• Bullet weight is 190 grains, a heavy-for-caliber projectile that carries useful energy at subsonic speed.
• The bullet is the Sub-X, a lead-core design with a gilding metal jacket made for reliable expansion at low velocity.
• A Flex Tip insert sits inside the hollow point cavity and helps the bullet expand when the impact speed is low.
• Muzzle velocity is 1050 fps from a 16-inch test barrel, below the speed of sound for quiet, predictable performance.
• Muzzle energy is 465 ft-lb, a figure that falls to 420 ft-lb at 100 yards.
• The G1 ballistic coefficient is .437, helping the heavy bullet hold its speed downrange.
• Sectional density is .286, which supports penetration from a bullet this heavy for its caliber.
• Hornady lists the application as medium game and personal defense, so it covers both field and home use.
• Box quantity is 20 rounds, the standard package for this Sub-X load.

Frequently Asked Questions

Is this ammunition made for suppressors? It is loaded to stay below the speed of sound, and Hornady says its subsonic powders give a low flash signature that works either suppressed or unsuppressed.

What bullet does this .300 Blackout load use? A 190-grain Sub-X with a lead core, a gilding metal jacket and a Flex Tip insert in the hollow point.

How fast is the 190gr Sub-X load? Hornady rates it at 1050 fps at the muzzle from a 16-inch test barrel, dropping to 998 fps at 100 yards.

Buy the Hornady Subsonic .300 Blackout 190gr Sub-X Ammunition

Choose this load when you want a heavy subsonic bullet that still expands. Order it from our Lubbock, Texas gun shop alongside more rifle ammunition for fast, insured shipping.