The Sig Sauer P365 Replacement Barrel (brand part no. BBL3659) is a factory 9mm Luger barrel machined from black nitride steel and built specifically to fit the P365 micro-compact platform. Sig Sauer holds the barrel to a non-threaded muzzle and a 3.1-inch length, matching the factory barrel the P365 ships with, so slide cycling and lockup stay consistent with the pistol’s original geometry. As a genuine Sig Sauer part, it’s a straightforward, factory-correct option for P365 owners replacing a worn barrel or building out a spare.

Key Specifications

• Chambered in 9mm Luger.
• Barrel measures 3.1 inches.
• Machined from black nitride steel.
• Non-threaded muzzle.
• Sold as a genuine Sig Sauer factory replacement barrel for the P365.

Frequently Asked Questions

What caliber is this barrel chambered in? 9mm Luger.

Is the muzzle threaded? No, it has a non-threaded muzzle.

Which pistol does it fit? The Sig Sauer P365.

Buy the Sig Sauer P365 Replacement Barrel

Bring your P365 back to factory spec with a genuine Sig Sauer barrel. Order it from our Sig Sauer lineup, part of our handgun barrels selection, at our Lubbock, Texas gun shop for fast, direct shipping.