The Odin Works 9mm AR9 Barrel (brand part no. B9MM75) is a 7.5-inch, medium-profile stainless steel barrel built for blowback-operated AR9 pistols chambered in 9mm Luger, cut with a 1:10 twist rate and threaded 1/2-28 at the muzzle. It is machined to work with either Colt-pattern or Glock-pattern magazine-fed AR9 lowers, giving builders flexibility in which magazine system they run. At 7.5 inches, this barrel is intended for pistol-configured lowers or ATF-approved SBR lowers only; installing it under a shoulder stock without prior NFA approval would create an unregistered short-barreled rifle. Odin Works builds this barrel specifically for the blowback AR9 platform rather than adapting a rifle-caliber barrel, which keeps reliability high in a pistol-caliber carbine.

Key Specifications

• Chambered in 9mm Luger for blowback-operated AR9 builds.
• 7.5-inch medium-profile barrel length.
• 1:10 twist rate suited to common 9mm bullet weights.
• Finished in stainless steel.
• Muzzle threaded 1/2-28 for standard 9mm muzzle devices.
• Compatible with both Colt-pattern and Glock-pattern AR9 lowers.

Frequently Asked Questions

Can this barrel be installed on a stocked rifle lower? No. At 7.5 inches, it is intended for pistol-configured or ATF-approved SBR lowers only; installing it under a shoulder stock without prior NFA approval would create an unregistered short-barreled rifle.

Which magazine systems does this barrel work with? It is machined to work with either Colt-pattern or Glock-pattern AR9 lowers.

Is the muzzle threaded? Yes, 1/2-28 for standard 9mm muzzle devices.

Buy the Odin Works AR9 Pistol Barrel

Build a compact 9mm AR pistol around a barrel purpose-made for blowback reliability. Order this Odin Works barrel from our AR barrel selection, and our Lubbock, Texas team will get it ready to ship as soon as it’s available.