Faxon Sig P320 Fullsize 9mm Flame Flute Threaded Barrel - Black

If you're running a Sig P320 Fullsize and want to boost accuracy, reliability, and shot longevity, a quality replacement barrel is one of the smartest upgrades you can make. The Faxon Sig P320 Fullsize 9mm Flame Flute Threaded Barrel is a precision drop-in upgrade that replaces your factory tube with a match-grade component built to tighter tolerances and better materials. Faxon machines these barrels in-house from stress-relieved 416-R stainless steel, then coats them with black nitride to boost lubricity, wear resistance, and service life—qualities you won't find in most factory barrels.

What makes this barrel stand out is the combination of precision engineering and real-world shootability. The threaded muzzle (1/2x28 TPI) opens the door to suppressors, muzzle brakes, or flash hiders, letting you customize your P320 for your specific mission. The flame-fluted profile reduces weight and heat dissipation without sacrificing rigidity, and the 11-degree target crown ensures consistent bullet seating and accuracy. Button rifling with a 1:10 twist is conventionally rifled, meaning it runs reliably with all ammunition types—including cast lead—so you're not locked into match-grade rounds to realize the accuracy gains.

Installation is straightforward: this is a true drop-in barrel for factory-spec P320 Fullsize slides, requiring zero gunsmithing. The improved lockup over factory tolerances translates to more consistent velocity, tighter groups, and a noticeably cleaner trigger feel once you're behind the gun.

Key Features

• Drop-in fit for Sig P320 Fullsize slides—no gunsmithing required
• Stress-relieved 416-R stainless steel for durability and accuracy
• Black nitride finish resists wear and improves lubricity
• Threaded muzzle (1/2x28 TPI) for suppressors or muzzle devices
• Flame-fluted profile for reduced weight and optimized heat management
• 11-degree target crown for consistent accuracy
• Button rifled with conventional rifling—reliable with all 9mm ammunition types
• Match-grade tolerances for superior lockup and consistency versus factory barrels

Specifications

Frequently Asked Questions

Will this barrel fit my Sig P320 Fullsize without modification?

Yes. This is a drop-in replacement designed to fit factory-spec P320 Fullsize slides with zero gunsmithing.

Can I use cast lead ammunition in this barrel?

Yes. The conventional button rifling makes this barrel safe and reliable with all 9mm ammunition types, including cast lead rounds.

Is the muzzle threaded, and what thread pitch is it?

Yes, the barrel features a 1/2x28 TPI threaded muzzle, which is the standard 9mm suppressor thread pattern. It accepts suppressors, muzzle brakes, flash hiders, and other muzzle devices.

What's the advantage of the flame-fluted profile?

The flame flutes reduce weight and improve heat dissipation while maintaining barrel stiffness, contributing to better accuracy and a lighter feel without compromising precision.