8.6 Blackout Ammo
The 8.6 Blackout is a .338-caliber cartridge engineered by Q LLC to deliver both supersonic and subsonic performance from an AR-10 platform — purpose-built from the ground up for suppressed use. Subsonic loads push 250–300gr .338 bullets at 1,050 fps, producing hearing-safe terminal performance far superior to subsonic 9mm or .300 Blackout. Supersonic loads drive 135–175gr projectiles at 2,350–2,700 fps for hunting and extended-range work. Impact Guns stocks ammo from Q LLC, Maxim Defense, and select specialty manufacturers.
Read our full 8.6 Blackout Ammo Buying Guide ↓
8.6 Blackout vs. .300 Blackout: Why Step Up to .338 Caliber?
The .300 Blackout fires a .308-caliber bullet — subsonic loads top out around 220 grains at roughly the same velocity. The 8.6 Blackout fires a .338-caliber bullet with subsonic loads reaching 250–300 grains. That mass advantage is decisive at close range: the 8.6 Blackout hits harder suppressed than .300 Blackout hits unsuppressed. For hogs, deer, or defensive use where you want genuine stopping power without ear protection, the 8.6 Blackout makes a compelling case. The trade-off is that it requires an AR-10-platform rifle rather than the lighter, more common AR-15.
Supersonic vs. Subsonic 8.6 Blackout: Choosing Your Load
Supersonic 8.6 Blackout loads (135–175gr at 2,350–2,700 fps) are flat-shooting hunting and target rounds suitable for use at 400+ yards. They cycle the action reliably and produce a conventional report — ear protection required. Subsonic loads (250–300gr at 1,040–1,050 fps) are the cartridge’s primary use case — hearing-safe with a quality suppressor, delivering .338-caliber energy at close to moderate ranges. Both load types are designed to cycle the same properly tuned 8.6 Blackout upper without adjustment, just like .300 Blackout does in a standard AR-15.
Best 8.6 Blackout Ammo Brands
Q LLC and Maxim Defense are the primary manufacturers of loaded 8.6 Blackout ammunition. Maxim Defense SBA (Short Barrel Ammunition) is a match-grade solid copper load designed specifically for the 8.6 Blackout’s short-barrel platforms. Q LLC produces both supersonic and subsonic loads tuned for their Boombox platform. As the cartridge grows in adoption, additional manufacturers are entering the market — availability is improving steadily. For high-volume practice, handloading with .338 Lapua Magnum-derived brass trimmed to spec is the most cost-effective approach.
8.6 Blackout and Suppressors: The Complete System
The 8.6 Blackout was designed from the ground up as a suppressed cartridge — subsonic use is its primary mission. A quality .338-caliber or large-bore multi-caliber suppressor is essentially required to realize the full potential of the round. Since January 1, 2026, the NFA $200 tax stamp has been eliminated, removing the primary cost barrier for building a dedicated suppressed 8.6 Blackout system. See our suppressors page for compatible options, and our 8.6 Blackout rifles page for platform options.
Related Ammo & Platform Pages
For comparison with related suppressor-optimized cartridges, see .300 Blackout ammo. For .338-caliber long-range cartridges, see .338 Lapua ammo. For rifles chambered in 8.6 Blackout, see our 8.6 Blackout rifles page. For the Q LLC platform that originated the cartridge, see our Q LLC page.