8.6 Blackout
The 8.6 BLK round was imagined and developed by Q.
When imagining 8.6 BLK, a good starting point is to think of 8.6 BLK as 300 BLK's "Big Brother." However, it's much more than just an upgrade on 300 BLK.
8.6 BLK is re-imagining "energy on target" by employing a fast 1:3 twist rate (compare to common 1:7 and 1:8 twist for calibers like 5.56 NATO or 300 BLK).
FAXON 8.6 BLACKOUT PRODUCTS
8.6 Blackout Barrels, Bolts & Components
The 8.6 Blackout (also commonly searched as 8.6 BLK) was designed from the ground up as a heavy-for-caliber, suppressed-first cartridge—and it demands the right components to perform as intended. This page serves as the authoritative guide to building an 8.6 Blackout rifle using Faxon Firearms’ in-house manufactured barrels and components.
Faxon Firearms is a family-owned American manufacturer, producing precision firearm components in Greater Cincinnati, Ohio. Our engineering roots extend back to 1978 across aerospace, defense, and advanced manufacturing—experience directly applied to demanding cartridges like 8.6 Blackout.
What Makes 8.6 Blackout Different?
Unlike traditional .30-caliber blackout cartridges, 8.6 Blackout is optimized for extreme subsonic mass, fast twist rates, and suppressed use. Bullet stabilization, gas system tuning, and barrel design are not optional—they are critical.
- Designed for 300+ grain subsonic projectiles
- Requires very fast twist rates for stability
- Performs best in short-barreled, suppressed platforms
- Commonly built on .308-sized receiver sets
Faxon 8.6 Blackout Barrels
Faxon 8.6 Blackout barrels are manufactured entirely in-house and engineered specifically for suppressed reliability, projectile stability, and real-world accuracy.
- Fast Twist Rates optimized for heavy subsonic bullets
- Precision-rifled bores for consistent stabilization
- Gas system tuning intended for suppressed operation
- Available in lengths suited for SBR and compact rifle builds
Whether you’re building a dedicated suppressed hunting rifle or a compact tactical platform, Faxon barrels remove the guesswork from 8.6 Blackout performance.
Suppressor & Gas System Considerations
8.6 Blackout is fundamentally a suppressor-driven cartridge. Barrel selection, gas system tuning, and suppressor choice must be considered together.
- Designed to pair with low-backpressure suppressors
- Proper gas system selection reduces bolt speed and gas blowback
- Thread compatibility must support large-bore suppressor mounts
Faxon suppressor-ready barrels and compatible mounting solutions ensure a stable, repeatable setup without excessive tuning or reliability issues.
Who 8.6 Blackout Is (and Is Not) For
8.6 Blackout is ideal for:
- Suppressed hunting applications
- Users prioritizing maximum subsonic energy
- Short-barreled rifle known-distance engagements
8.6 Blackout is not ideal for:
- High-velocity or long-range supersonic shooting
- Lightweight AR-15 platforms
- Users unwilling to tune for suppressed operation
Is 8.6 Blackout the same as 8.6 BLK? ▾
Yes. 8.6 BLK is a commonly used shorthand for 8.6 Blackout. Both refer to the same cartridge.
What twist rate is required for 8.6 Blackout? ▾
8.6 Blackout requires very fast twist rates to properly stabilize heavy subsonic bullets. Faxon barrels are engineered specifically for this requirement.
Is 8.6 Blackout designed to be suppressed? ▾
Yes. 8.6 Blackout was developed with suppressed operation as a primary design goal.
Are Faxon 8.6 Blackout barrels made in the USA? ▾
Yes. All Faxon barrels are manufactured in-house in Greater Cincinnati, Ohio.
Do I need a .308-sized receiver set for 8.6 Blackout? ▾
Yes. 8.6 Blackout is typically built on .308-sized receiver platforms due to cartridge dimensions and bolt requirements.
8.6 BLK Coverage