The Lead & Steel 9mm AR9 barrel (brand part no. LS9MM5.5-28) is a 5.5-inch straight profile barrel built for blowback 9mm AR builds, turned from 4150 Chrome-Moly-Vanadium steel and coated in a QPQ Black Nitride finish.

Key Specifications

• Chambered in 9mm for blowback-operated AR9 builds.
• Cut to a 5.5-inch overall length.
• Rifled with a 1:10 twist rate.
• Straight profile contour, sized for 9mm blowback uppers rather than a gas-operated rifle profile.
• Turned from 4150 Chrome-Moly-Vanadium steel for durability under repeated firing.
• Finished with a QPQ Black Nitride coating for corrosion and wear resistance.
• Runs on a straight blowback gas system, so no gas block or gas tube is needed.
• Compatible with standard mil-spec AR-15 upper receivers set up for a 9mm blowback conversion.
• Also compatible with dedicated AR9-specific upper receivers.

Frequently Asked Questions

Does this need a gas block or gas tube? No. It runs on a straight blowback system, so no gas block or gas tube is required.

Will it fit a standard AR-15 upper? Yes. It works with standard mil-spec uppers set up for a 9mm blowback conversion as well as dedicated AR9 uppers.

What twist rate does it use? It uses a 1:10 twist rate.

Buy the Lead & Steel 9mm AR9 Barrel, 5.5-Inch Straight Profile

Order the Lead & Steel 9mm AR9 barrel from our Lubbock, Texas gun shop for a durable, nitride-finished blowback build barrel. See the rest of our AR barrels lineup for other AR barrel lengths and calibers.