Faxon Ar15 Barrel 300Blk - 7.5" 1:8 Gunner Profile Blk
The Faxon AR-15 barrel in .300 Blackout with a 7.5" Gunner profile is purpose-built for shooters who want a short-barreled rifle that doesn't sacrifice accuracy or handling. This barrel brings together Faxon's reputation for precision machining with a profile geometry that balances weight savings and rigidity—critical for both supersonic and subsonic .300 BLK shooting. Whether you're building a pistol-length AR or a compact carbine, this is a barrel that performs across the board.
The Gunner contour is where the engineering shines. From the muzzle back to the gas block, Faxon uses a slim profile to keep the rifle nimble and easy to maneuver in tight spaces. Behind the gas block, the profile thickens to provide the meat needed for sustained accuracy during longer shooting sessions and to resist heat distortion. It's a smart design choice that avoids the dead weight of a thick profile up front while keeping the barrel rigid where it matters most.
The 7.5" length is optimized for pistol-length gas systems, making it ideal for short-barreled rifle (SBR) builds or AR pistols. The 1-in-8" twist rate stabilizes the full range of .300 Blackout ammunition, from heavy subsonic rounds to lighter, faster projectiles. The barrel is finished in QPQ Nitride with an NP3-coated extension for durability and corrosion resistance, and it ships ready to go with an 11° target crown and 5/8-24 muzzle threads.
Built from 4150 Chrome-Moly steel and SAAMI-chambered, this is a quality Faxon barrel that will serve you reliably whether you're running it suppressed for quiet backstop work or unsuppressed for tactical rifle training.
Key Features
- 7.5" barrel length optimized for pistol-length gas tubes
- Gunner profile: slim forward section for handling, thicker rear section for rigidity and heat resistance
- 1-in-8" twist rate stabilizes subsonic and supersonic .300 Blackout ammunition
- 4150 Chrome-Moly steel construction machined to tight tolerances
- QPQ Nitride finish with NP3-coated barrel extension for corrosion protection
- 11° target crown for consistent accuracy
- 5/8-24 TPI muzzle threads
- M4 feed ramps on barrel extension
- Gas port drilled for pistol-length gas system
Specifications
| Caliber | .300 AAC Blackout (300 BLK) |
| Barrel Length | 7.5" |
| Contour | Gunner Profile |
| Twist Rate | 1 in 8" |
| Material | 4150 Chrome-Moly Steel |
| Gas System | Pistol Length |
| Gas Port Diameter | .104" |
| Gas Block Journal Diameter | .750" |
| Muzzle Outside Diameter | 1.9" |
| Muzzle Thread Pattern | 5/8-24 TPI |
| Muzzle Crown | 11° Target Crown |
| Barrel Extension | M4 Feed Ramps |
| Finish | Black QPQ Nitride with NP3-Coated Extension |
| Chamber | SAAMI |
Frequently Asked Questions
What gas system does this barrel use?
This barrel is drilled and timed for a pistol-length gas tube, making it ideal for short-barreled rifle builds and AR pistol configurations.
Will this barrel stabilize both subsonic and supersonic .300 Blackout ammo?
Yes. The 1-in-8" twist rate is designed to stabilize the full range of .300 BLK ammunition, including heavy subsonic rounds and lighter, faster projectiles.
What's the difference between the Gunner profile and a standard pencil barrel?
The Gunner profile combines a slim forward section (muzzle to gas block) for light weight and handling with a thicker rear section (gas block to extension) for rigidity and heat resistance during sustained fire. This hybrid approach avoids excess weight up front while maintaining accuracy over longer shooting sessions.
What muzzle thread pattern does this barrel have?
The barrel features 5/8-24 TPI threads, the standard pattern for .300 Blackout suppressors and muzzle devices.

