4.5" 9MM Pistol Length AR15 Barrel, Modern Series

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Shipping Weight:
0.60 LBS
$8.55 (Fixed Shipping Cost)
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Ballistic Advantage 4.5" 9MM Pistol Length AR15 Barrel, Modern Series

9mm chambered modern series barrel, machined from 4150 chrome moly vanadium steel with a QPQ corrosion resistant finish and 1/2-28 x .400 full profile threads.

  • Designed to work with both Colt/RR and Glock style AR builds.

  • Compatible with standard mil-spec uppers. There are also numerous dedicated 9mm upper options that work.

  • Requires the use of a unique magwell conversion (Colt/Rock River style) with UZI mags or a dedicated 9mm lower with Glock mags.

  • 9mm on an AR15 platform operates by blowback and does not need a gas block or gas tube.

  • Threaded 1/2x28 instead of 1/2x36 to give you greater versatility when choosing a suppressor.

  • Integrated feed ramp and barrel extension.

  • Since the “barrel extension” is an integral part of the barrel, the length stated is the true overall length. For example, an 11” 9mm barrel has the same outer dimensions/length as a 10.5” 5.56 barrel.

  • IMPORTANT! A standard 1/2x28 flash hider will not have enough clearance for a 9mm round to pass.

  • IMPORTANT! Before installing a muzzle device, ensure a 9mm round will drop freely through the muzzle device bore.

You may use this barrel with a lower receiver that is a registered SBR, Machine Gun, or Pistol. Possession of this barrel along with a Non-NFA lower receiver is prohibited, except when installed on a pistol configuration firearm.

Additional Info:




4150 chrome moly vanadium




QPQ corrosion resistant

Gas System Length


Gas Block Journal

Blowback gas system - no gas block

Twist Rate

1:10 inches


1/2x28 threaded


9.6 oz.