P365 3.77'' Bbl 9Mm 1-2-28'' Threaded Stainless

The Zaffiri Precision P365 3.77" barrel in 9mm with 1/2x28 threads is a match-grade drop-in upgrade built for Sig Sauer P365 shooters who want tighter groups and reliability out of the box. Made from 416R stainless steel and manufactured to exacting standards in the USA, this threaded barrel transforms your compact carry gun into a more accurate platform without gunsmithing—just swap it in and shoot. Whether you're running a suppressor, threading your carry gun for a brake, or simply want a precision barrel that handles lead, plated, and jacketed ammunition equally well, Zaffiri's reputation for accuracy and attention to detail makes this a no-compromise choice.

The engineering behind this barrel sets it apart from stock alternatives. Zaffiri cuts the 6-groove rifling via broach cut and stress-relieves and heat-treats it to RC 40-42 hardness for durability and consistency. The chamber is fully supported—critical for safety and longevity—and the polished bore and chamber ensure smooth feeding and reliable function across ammunition types. An oversized lock-up area and improved feed ramp design further refine reliability, while a target crown delivers the precision accuracy shooters expect from a match-grade barrel.

The 3.77" length preserves the compact profile P365 owners depend on for carry, and the 1/2x28 threads are standard on most 9mm suppressors and muzzle devices. A thread protector is included, so you're ready to use the barrel right away whether suppressed or not. The stainless finish resists corrosion and pairs well with modern P365 setups, though the large "ZP" logo machined into the barrel adds a touch of brand identity.

Key Features

• Match-grade precision manufacturing for improved accuracy over factory barrels
• 416R stainless steel, stress-relieved and heat-treated to RC 40-42
• 6-groove broach-cut rifling with 1/10 left-hand twist
• Fully supported chamber and improved feed ramp design
• Polished bore and chamber for reliable feeding of all bullet types
• Target crown for precise accuracy
• 1/2x28 threaded muzzle for suppressors and brakes
• Drop-in fit—no modifications required
• Thread protector included
• Made in the USA

Specifications

Frequently Asked Questions

Will this barrel fit my Sig Sauer P365 without any modifications?

Yes. This is a drop-in barrel designed for the P365—no gunsmithing or fitting required. Simply remove the factory barrel and install the Zaffiri barrel in its place.

Can I use a suppressor with this barrel?

Yes. The barrel features a 1/2x28 threaded muzzle, which is the standard thread pitch for 9mm suppressors and muzzle devices. A thread protector is included for when you're running the barrel unsuppressed.

What ammunition types does this barrel handle reliably?

The polished bore and chamber are designed to feed and function reliably with lead, plated, and jacketed bullets. It's chambered to 9mm SAAMI specifications.

Is this barrel made in the USA?

Yes. Zaffiri Precision manufactures this barrel in the USA to match-grade standards.