Hornady Black 300 AAC Blackout Ammo 208 Grain Hornady A-Max Polymer Tip Box of 20

Last reviewed: 2026-04-18 by Jake Terry, FFL07/SOT3, NRA-certified firearms instructor.

For suppressed carbine and pistol shooters, Hornady Black 300 AAC Blackout 208gr A-Max subsonic ammo delivers velocity below the sound barrier without sacrificing terminal performance. Engineered to cycle reliably in direct impingement and gas piston AR-15 platforms, this load pairs a 208-grain polymer-tipped projectile with powder metered for 1020 fps from a 16-inch test barrel. The A-Max bullet—originally designed for match competition—carries a 0.648 G1 ballistic coefficient and 0.313 sectional density, stabilizing in standard 1:7 or 1:8 twist barrels while maintaining supersonic flight at subsonic launch speeds. Hornady brass cases and non-corrosive boxer primers support field reloading across multiple firing cycles.

Built for the Box

Hornady manufactures the Black line at its Grand Island, Nebraska facility, combining match-grade A-Max projectiles with powder charges optimized for the 300 Blackout case volume. The polymer tip initiates controlled expansion on impact while the boat-tail base reduces drag in flight. Each 20-round box ships with new brass cases sized to SAAMI minimum chamber dimensions, ensuring reliable chambering in factory barrels and aftermarket match chambers. For shooters running subsonic loads through direct-thread or quick-detach suppressors, the 1020 fps muzzle velocity stays approximately 100 fps below the 1125 fps threshold where sonic crack begins. Hornady lists this load’s intended use as self-defense, though the high ballistic coefficient also suits precision training inside 300 yards.

The Numbers

Velocity was measured from a 16-inch barrel; shorter pistol barrels (8-10 inches) typically yield 950-1000 fps, maintaining subsonic flight. The 0.648 BC places this projectile in the match-grade class, outperforming flat-base designs past 200 yards. Shooters reloading these cases can seat bullets to 2.260 inches overall length for magazine feeding in STANAG and Magpul PMAG30 magazines. For more subsonic and supersonic options, browse our full 300 Blackout ammo inventory.

Who It’s For

This load suits suppressed carbine and pistol shooters prioritizing hearing-safe operation without sacrificing accuracy inside 300 yards. The A-Max projectile’s polymer tip and boat-tail base deliver predictable flight in wind, making it suitable for recreational target work and hog hunting where close-range precision matters. Reloaders benefit from the once-fired brass; Hornady cases typically survive 5-7 reload cycles before primer pockets loosen. Avoid this load for unsuppressed barrels shorter than 8 inches—gas systems may short-stroke without suppressor back-pressure.