8.6 Blackout Ammo — In Stock, Subsonic & Supersonic

8.6 Blackout (8.6 BLK) is the heavy-hitting, suppressor-first cartridge built by Q, LLC — the same team that gave shooters the .300 Blackout. Built on a shortened 6.5 Creedmoor case necked up to a .338 projectile, it was designed from day one to push heavy bullets quietly through short barrels. The result is deep penetration and hard-hitting terminal performance that subsonic .30-caliber rounds simply can’t match.

Below you’ll find the 8.6 Blackout ammo we keep in stock — subsonic loads for maximum suppression and supersonic loads when you need more velocity, in grain weights from 210gr up to 342gr. Every order ships fast with secure checkout, and our team can help you match the right load to your barrel and twist rate.

What Is 8.6 Blackout?

8.6 Blackout (8.6×43mm) fires a .338-diameter bullet — the same caliber class as .338 Federal — but it’s optimized for subsonic, suppressed shooting rather than long-range velocity. Because it’s based on the 6.5 Creedmoor case head, it drops into AR-10 / SR-25 pattern rifles with a barrel and bolt change, and it’s a natural fit for purpose-built bolt actions. Its signature feature is an extremely fast twist rate (often around 1:3), which is what lets it stabilize the very heavy, very long subsonic bullets that a standard .30-caliber twist would tumble.

Subsonic vs. Supersonic 8.6 Blackout

Subsonic (≈1,000 fps): The reason 8.6 BLK exists. Heavy 285–342gr bullets stay below the speed of sound, so paired with a suppressor they’re dramatically quieter — no supersonic crack. This is the load for suppressed hunting and stealth shooting, and the heavy bullets still carry serious energy and penetration.
Supersonic (210–250gr): Faster, flatter-shooting loads for when you want more reach and aren’t prioritizing maximum sound reduction. A 210gr Barnes TSX is a popular supersonic choice for expansion and penetration on game.

8.6 Blackout Grain Weights Explained

Grain weight	Typical velocity	Best for
210gr	Supersonic	Flatter trajectory, expansion, supersonic hunting
285gr	Subsonic	Suppressed shooting, balanced subsonic terminal performance
300gr	Subsonic	Suppressed target/match and hunting
342gr	Subsonic	Maximum-weight subsonic hunting, deep penetration on hogs and deer

What Is 8.6 Blackout Good For?

8.6 Blackout is built for suppressed hunting — hogs, deer, and predators at moderate range — and for short-barreled, suppressed tactical use where a quiet, hard-hitting round matters more than long-distance velocity. Hunters value its heavy subsonic bullets for the energy they retain and the penetration they deliver even at low velocity.

Will 8.6 Blackout Run in My Rifle?

8.6 BLK is an AR-10 / .308-pattern conversion (barrel + bolt) or a dedicated bolt-action cartridge — it does not run in an AR-15 or 5.56 magazine like .300 Blackout does. Confirm your barrel’s twist rate and length: the fast 1:3-class twist that purpose-built 8.6 barrels use is what stabilizes the heaviest subsonic loads. If you’re running a shorter barrel and a suppressor, subsonic loads are usually the way to go.

8.6 Blackout Ammo FAQ

Is 8.6 Blackout ammo subsonic or supersonic?

Both. 8.6 Blackout was designed primarily for heavy subsonic loads (285–342gr at around 1,000 fps) for suppressed shooting, but supersonic loads (around 210gr) are also available for flatter trajectory and more velocity.

What’s the best 8.6 Blackout grain weight for hunting?

For suppressed hunting, heavy subsonic loads from 285gr to 342gr are the most popular for their penetration and retained energy. For supersonic hunting with more reach and expansion, a 210gr load like the Barnes TSX is a common choice.

Will 8.6 Blackout work in an AR-15?

No. Unlike .300 Blackout, 8.6 Blackout is built on the 6.5 Creedmoor case and runs in AR-10 / .308-pattern rifles (with a barrel and bolt change) or in bolt-action rifles — not in a standard AR-15 or 5.56 magazine.

What bullet diameter does 8.6 Blackout use?

8.6 Blackout fires a .338-caliber (8.585mm) bullet, the same diameter as cartridges like .338 Federal, but optimized for subsonic, suppressed use.

Who makes 8.6 Blackout?

The cartridge was developed by Q, LLC — the same company behind the .300 Blackout. Loaded ammunition is produced by several manufacturers, and we stock multiple loads across grain weights.