
Availability: In Stock
Current Stock: Out of stock
The Ballistic Advantage AR-15 Modern Series 5.5\" Barrel brings serious versatility to 9mm AR builds. This is a true blowback-operated 9mm AR barrel, not a 5.56 conversion—it's engineered from 4150 Chrome Moly Vanadium steel with a QPQ corrosion-resistant finish to handle repeated cycling and suppressor use without breaking the bank. The integrated barrel extension and feed ramp mean you get a complete, purpose-built package that simplifies your build and ensures reliable feeding with either Colt/Rock River or Glock-style magwell systems.
One of the smartest features of a 9mm AR is what it doesn't need: a gas block, gas tube, or adjustable system. The blowback design keeps your upper simple and your costs down. Threading is 1/2x28, giving you flexibility when selecting a suppressor. The 1:10 twist rate is optimized for standard 9mm projectiles. Just remember the golden rule—before you thread on any muzzle device, drop a 9mm round through the bore to confirm clearance. A standard 5.56 flash hider won't work here.
Compatibility matters with 9mm AR builds, and this barrel plays well with mil-spec uppers and dedicated 9mm upper receivers alike. If you're running a magwell conversion setup, you'll pair this with either UZI mags (Colt/RR style) or dedicate to a Glock mag lower. The true overall length includes the integral extension, so this 5.5\" barrel has the same footprint as a 5\" 5.56 AR pistol—useful to know when planning your build or configuring an SBR.
This is the right choice if you're building a 9mm AR for plinking, home defense training, or suppressed shooting without the gas system hassle of a 5.56 platform.
| Barrel Length | 5.5\" |
| Chambering | 9mm |
| Material | 4150 Chrome Moly Vanadium |
| Finish | QPQ Corrosion Resistant |
| Muzzle Threading | 1/2x28 |
| Twist Rate | 1:10\" |
| Gas System | Blowback (no gas block required) |
| Magwell Compatibility | Colt/Rock River and Glock-style |
Yes. This barrel is compatible with mil-spec AR-15 uppers. However, you'll also have the option to use dedicated 9mm upper receivers if you prefer. You'll need either a magwell conversion (for UZI mags with Colt/Rock River lowers) or a dedicated 9mm lower receiver (for Glock mags).
No. This is a blowback-operated 9mm barrel, so it does not require a gas block, gas tube, or adjustable system. The design keeps your upper simple and cost-effective.
The barrel is threaded 1/2x28 and works with 9mm suppressors and compatible muzzle devices. Critically, you must ensure any device has adequate bore clearance for a 9mm round to pass freely—standard 5.56 flash hiders will not work. Always drop a 9mm round through the muzzle device bore before installation.
This 5.5\" barrel includes an integrated extension, so its true overall length and outer dimensions match approximately a 5\" 5.56 AR barrel. The stated 5.5\" length is the complete, finished size—useful for SBR or pistol configuration planning.

SKU: 194198861 • Weight: 0.62oz





Availability: In Stock
Current Stock: Out of stock
The Ballistic Advantage AR-15 Modern Series 5.5\" Barrel brings serious versatility to 9mm AR builds. This is a true blowback-operated 9mm AR barrel, not a 5.56 conversion—it's engineered from 4150 Chrome Moly Vanadium steel with a QPQ corrosion-resistant finish to handle repeated cycling and suppressor use without breaking the bank. The integrated barrel extension and feed ramp mean you get a complete, purpose-built package that simplifies your build and ensures reliable feeding with either Colt/Rock River or Glock-style magwell systems.
One of the smartest features of a 9mm AR is what it doesn't need: a gas block, gas tube, or adjustable system. The blowback design keeps your upper simple and your costs down. Threading is 1/2x28, giving you flexibility when selecting a suppressor. The 1:10 twist rate is optimized for standard 9mm projectiles. Just remember the golden rule—before you thread on any muzzle device, drop a 9mm round through the bore to confirm clearance. A standard 5.56 flash hider won't work here.
Compatibility matters with 9mm AR builds, and this barrel plays well with mil-spec uppers and dedicated 9mm upper receivers alike. If you're running a magwell conversion setup, you'll pair this with either UZI mags (Colt/RR style) or dedicate to a Glock mag lower. The true overall length includes the integral extension, so this 5.5\" barrel has the same footprint as a 5\" 5.56 AR pistol—useful to know when planning your build or configuring an SBR.
This is the right choice if you're building a 9mm AR for plinking, home defense training, or suppressed shooting without the gas system hassle of a 5.56 platform.
| Barrel Length | 5.5\" |
| Chambering | 9mm |
| Material | 4150 Chrome Moly Vanadium |
| Finish | QPQ Corrosion Resistant |
| Muzzle Threading | 1/2x28 |
| Twist Rate | 1:10\" |
| Gas System | Blowback (no gas block required) |
| Magwell Compatibility | Colt/Rock River and Glock-style |
Yes. This barrel is compatible with mil-spec AR-15 uppers. However, you'll also have the option to use dedicated 9mm upper receivers if you prefer. You'll need either a magwell conversion (for UZI mags with Colt/Rock River lowers) or a dedicated 9mm lower receiver (for Glock mags).
No. This is a blowback-operated 9mm barrel, so it does not require a gas block, gas tube, or adjustable system. The design keeps your upper simple and cost-effective.
The barrel is threaded 1/2x28 and works with 9mm suppressors and compatible muzzle devices. Critically, you must ensure any device has adequate bore clearance for a 9mm round to pass freely—standard 5.56 flash hiders will not work. Always drop a 9mm round through the muzzle device bore before installation.
This 5.5\" barrel includes an integrated extension, so its true overall length and outer dimensions match approximately a 5\" 5.56 AR barrel. The stated 5.5\" length is the complete, finished size—useful for SBR or pistol configuration planning.
SKU: 194198861 • Weight: 0.62oz
