Sig Sauer P320 Full Size 9mm Luger Barrel, 5.5" 13.5mm LH Thread, Steel Black

The Sig Sauer P320 Full Size 9mm Luger barrel is a factory replacement component for your P320 full-size pistol. At 5.5 inches long with M13.5 x 1mm left-hand threads, this Nitron-finished steel barrel pairs seamlessly with your existing P320 full-size slide and grip module. Whether you're looking to refresh a worn barrel, experiment with different trigger jobs, or simply keep a spare on hand, a threaded replacement barrel opens up flexibility for your duty or competition setup.

Installation is straightforward for anyone comfortable field-stripping a pistol. Once you've confirmed the firearm is unloaded, remove the slide from the receiver and grip module, and the old barrel slides right out. The new barrel drops into place just as easily. The barrel ships with a thread protector cap—essential for safe handling and storage of the muzzle threads when you're not running a suppressor or muzzle device.

The left-hand threads on this barrel accommodate suppressors and other muzzle devices designed for counterclockwise mounting. The Nitron finish provides durable corrosion resistance and a professional appearance. This is genuine Sig Sauer factory spec hardware, not an aftermarket approximation—it maintains the same tight tolerances and reliability you expect from a P320 platform pistol.

Key Features

• 5.5-inch length for full-size P320 compatibility
• M13.5 x 1mm left-hand threads for suppressor and muzzle device mounting
• Durable Nitron steel finish resists corrosion
• Includes thread protector cap
• Factory Sig Sauer component—consistent tolerances and reliability

Specifications

Frequently Asked Questions

Will this barrel fit my P320 Compact or Subcompact?

No. This is a full-size barrel designed specifically for P320 full-size models. Compact and Subcompact variants use different barrel lengths and won't accept this component.

Does this barrel come with a suppressor?

No. The barrel includes only a thread protector cap. You'll need to source a suppressor or muzzle device separately if desired.

What does "left-hand thread" mean for mounting?

Left-hand threads reverse the standard direction—suppressors and muzzle devices screw on counterclockwise (when viewed from behind the muzzle). This is the factory thread direction for this barrel.

How do I replace the barrel?

Ensure the firearm is unloaded, remove the slide from the receiver and grip module, and slide out the existing barrel. The new barrel installs by reversing the process. If you're unfamiliar with P320 disassembly, consult your manual or seek guidance from a qualified gunsmith.