The Faxon Firearms Duty Series 9mm Barrel for Sig Sauer P365XL is a rugged, precision-crafted upgrade built for shooters who demand duty-grade reliability, improved accuracy, and threaded-barrel versatility in their everyday carry pistol. Machined from 4150 CMV steel and finished in a tough black QPQ nitride, this drop-in 9mm barrel (Part # 365A910NXNOQ-T, UPC 816341028494) is designed specifically to fit the Sig Sauer P365XL, giving you a direct replacement that’s tougher, slicker, and more precise than stock. faxonfirearms.com+1
Whether you’re building a compensated carry gun, setting up a suppressed P365XL (where legal), or just want a barrel you can trust for thousands of rounds, the Faxon Duty Series P365XL threaded barrel delivers performance you can feel every time you pull the trigger.
Duty-Grade Upgrade for Your Sig Sauer P365XL
This barrel is purpose-built to fit the Sig Sauer P365XL, giving you factory-style compatibility with a serious performance bump:
Handgun type: Sig Sauer P365XL
Caliber: 9mm Luger
Profile: Drop-in, no gunsmithing required for factory-spec slides faxonfirearms.com+1
Faxon machines each barrel in-house in their Greater Cincinnati, Ohio facility, ensuring tight quality control, consistent tolerances, and a better-than-factory lockup that helps tighten your groups and enhance reliability. faxonfirearms.com+1
4150 CMV Steel with Black Nitride – Built to Run Hard
The Duty Series P365XL barrel is made from stress-relieved 4150 CMV steel, the same type of tough, heat-resistant steel commonly used in hard-use rifle barrels. Palmetto State Armory+1
It’s then treated with a salt bath black nitride finish inside and out, which:
Increases surface hardness and wear resistance
Improves corrosion resistance for carry in sweat, humidity, and rain
Enhances lubricity to help the pistol cycle smoothly and clean up easier after long range sessions Palmetto State Armory+1
If you rely on your P365XL for concealed carry or duty use, this is the type of barrel you want running at the heart of your pistol.
Threaded Barrel Versatility – Ready for Compensators & Suppressors
This Duty Series model is the threaded P365XL barrel, giving you the flexibility to run:
Compensators to reduce muzzle rise and speed up follow-up shots
Suppressors (where legal and with appropriate components) for reduced blast and softer shooting
Other 9mm muzzle devices compatible with its standard 1/2x28 thread pitch Grayguns+1
The barrel length is approximately 4.2" to accommodate the threads, giving you a bit more real estate at the muzzle while still maintaining a compact, carry-friendly footprint. Midwest Gun Works
Note: As with any threaded barrel, always use a proper thread protector or muzzle device when carrying or shooting to protect the threads.
1:10 Twist, Conventional Rifling & Target Crown for Accuracy
Faxon tuned this barrel for real-world accuracy with several key features:
1:10 twist rate – A proven twist for stabilizing a broad range of common 9mm bullet weights used in defensive, training, and match ammunition. performancetriggers.com+1
Conventional rifling – Unlike polygonal rifling, Faxon’s conventional rifling allows the safe use of a wider variety of ammunition types, including properly loaded cast lead bullets (within safe loading practices). faxonfirearms.com+1
11-degree target crown – A precision-machined crown that protects the bore at the muzzle and promotes consistent, even gas release for tighter groups and repeatable shot placement. Midwest Gun Works+1
Combined, these features make this barrel an excellent choice for anyone who wants to get the most accuracy possible out of a micro-compact pistol like the P365XL.
True Drop-In Installation – Better Lockup Than OEM
The Faxon Duty Series P365XL barrel is engineered as a drop-in upgrade:
Installs using standard field-stripping tools and basic skills
Does not require permanent modifications or fitting on factory slides
Uses better-than-factory tolerances for a tighter, more consistent lockup than many OEM barrels can provide faxonfirearms.com+1
This improved lockup is a key reason many users see tangible accuracy gains when they swap to a Faxon barrel, especially when combined with good ammo and fundamentals.
Perfect for Carry, Training, and Custom Builds
The Duty Series 9mm P365XL threaded barrel is ideal for:
Concealed carry pistols – For shooters who want suppressor or compensator capability without sacrificing reliability. Gun Values Board
EDC / defensive training guns – Built to withstand high round counts, holster wear, and daily carry environments.
Competition and range builds – Add a comp, tune your recoil impulse, and enjoy improved mechanical accuracy.
Suppressor hosts (where legal) – Standard 1/2x28 threads make it easy to integrate into typical 9mm suppressor setups.
If you’re serious about getting more performance from your small carry pistol, this barrel turns the P365XL into a much more capable platform.
Key Specs – Faxon Duty Series 9mm Barrel for P365XL (Threaded)
Manufacturer: Faxon Firearms
Series: Duty Series
Part Number: 365A910NXNOQ-T
UPC: 816341028494 faxonfirearms.com+1
Firearm Fit: Sig Sauer P365XL
Caliber: 9mm Luger
Barrel Length: ~4.2" (threaded) Midwest Gun Works
Material: Stress-relieved 4150 CMV steel
Finish: Black QPQ / salt bath nitride, inside and out Palmetto State Armory+1
Twist Rate: 1:10
Rifling Type: Conventional
Muzzle Thread: 1/2x28 TPI
Crown: 11-degree target crown Midwest Gun Works+1
Profile: Drop-in, duty-grade handgun barrel
Why Choose the Faxon Duty Series P365XL Threaded Barrel?
Choose this barrel if you:
Want a reliable, duty-grade threaded barrel for your Sig P365XL
Need better consistency and accuracy than most factory barrels deliver
Prefer a tough 4150 CMV steel barrel with full nitride protection, inside and out
Plan to run a compensator or suppressor and want a proven 1/2x28 threaded option
Appreciate drop-in installation and better-than-OEM tolerances from a well-respected manufacturer
For concealed carriers, competitive shooters, and serious enthusiasts alike, the Faxon Firearms Duty Series 9mm Barrel, Fits Sig Sauer P365XL, 4150 CMV (365A910NXNOQ-T / 816341028494) is a smart, high-performance upgrade that adds accuracy, durability, and muzzle device versatility to one of the most popular micro-compact pistols on the market.
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