Glock 47740 45 Acp Fits 21 Gen4 Black Steel

The Glock 47740 is a threaded barrel replacement for Glock 21 Gen4 pistols chambered in 45 ACP. If you're running a suppressor or just want the option to add one down the road, swapping in a quality aftermarket barrel is one of the most straightforward upgrades you can make. This steel barrel is finished in black and threads directly onto your Gen4 frame—no gunsmithing required. Whether you're building a suppressed home-defense setup, a dedicated range gun, or simply want a spare barrel on hand, this gives you the flexibility to tailor your platform to your needs.

Glock's factory barrels are reliable workhorses, and this OEM-spec replacement maintains that standard. The threaded design opens up suppressor compatibility without compromising the integrity of your slide or frame. Installation takes minutes: field-strip your 21, swap the barrel, and you're ready to function-test. Because it's a direct fit for Gen4 models, you won't have to worry about fitment headaches or timing issues.

Whether you're a suppressor enthusiast, a defensive shooter wanting additional options, or someone who just appreciates having spares in the safe, this barrel is a solid investment in your 45 ACP platform's versatility.

Key Features

• Threaded design for suppressor compatibility
• Black steel construction
• Direct fit for Glock 21 Gen4 pistols
• 45 ACP chambering
• OEM-quality replacement barrel

Specifications

Frequently Asked Questions

Will this barrel work with my Glock 21 Gen3?

This barrel is spec'd for Glock 21 Gen4 pistols. While Gen3 and Gen4 frames share many commonalities, we recommend confirming compatibility with Glock or a qualified gunsmith before purchasing if you own a Gen3 model.

Can I use this barrel with a suppressor?

Yes—the threaded design is specifically intended for suppressor mounting. You'll need to verify that your suppressor is rated for 45 ACP and compatible with the thread pitch.

Is this barrel ready to install out of the box?

The barrel itself requires no additional work. Installation is a straightforward field-strip swap on your Glock 21 Gen4. If you're unfamiliar with barrel replacement, consult your pistol's manual or a qualified gunsmith.