Fits Glock 21 Gen 3-4 45ACP Barrel Threaded .578 x 28

Upgrade your Glock 21 with a purpose-built, drop-in replacement barrel designed for enhanced functionality. This precision-machined Glock barrel is engineered for shooters who demand versatility from their .45 ACP handgun. It directly replaces your factory barrel, adding the crucial capability of attaching muzzle devices like compensators or suppressors. For Gen 3 and Gen 4 Glock 21 owners, this is the straightforward component you need to expand your pistol’s role on the range or in a duty configuration.

Key Features

• Precision threaded muzzle with .578×28 TPI, the standard thread pitch for .45 caliber muzzle devices.
• Designed as a true drop-in fit for Glock 21 Gen 3 and Gen 4 models, requiring no gunsmithing for installation.
• Machined from high-strength, heat-treated stainless steel for durability and consistent performance.
• Features fully supported chamber geometry for improved cartridge case support and feeding reliability.
• Includes precision-cut rifling for consistent accuracy with a wide range of .45 ACP ammunition.
• Maintains all factory safety features and is designed for reliable lockup and smooth cycling.

Built For

This barrel is ideal for the Glock 21 owner who wants to legally configure their pistol for a suppressor or wants to reduce muzzle rise with a compensator. It’s also a solid choice for those seeking a durable, range-ready barrel that offers a fully supported chamber for hand-loaded or specialty ammunition.

Specifications

• Caliber: .45 ACP
• Compatibility: Glock 21, Generation 3 and Generation 4
• Thread Pitch: .578″ x 28 TPI
• Material: Heat-Treated Stainless Steel
• Finish: Matte Black or Stainless, depending on stock

FAQ

Is this a drop-in barrel, or does it require fitting?
This is designed as a drop-in barrel for the specified Glock 21 models. It should install directly into your factory slide without modification, though we always recommend checking headspace and function testing with your specific firearm.

Will this barrel work with a suppressor?
Yes, the .578×28 thread is the standard for .45 caliber suppressors. You must ensure your suppressor is rated for .45 ACP and that you have the proper piston or fixed mount for a fixed-barrel pistol application. Always verify local and federal regulations regarding suppressor ownership.