B&T USW-G20 Conversion Kit for Glock 20/21 - Ultimate Tactical Upgrade

The B&T USW-G20 conversion kit transforms your Glock 20 or Glock 21 into a compact carbine without swapping firearms. This conversion kit pairs the ergonomics and reliability of a full-size pistol with the control and accuracy benefits of a shoulder stock, giving you a genuinely versatile platform for training, competition, or duty use. The folding stock deploys in under a second, so you can run traditional pistol-length or transition to carbine configuration on demand — all without modification to your base gun.

B&T engineered this kit around the standard Glock rail system, so installation is straightforward on Gen 3, Gen 4, and Gen 5 frames in 10 mm Auto or .45 ACP. The design preserves your Glock's original open sights, letting you keep them zeroed and use them as a reliable backup. The kit also accommodates optional optics mounting, expanding your sight options for precision shooting while keeping the gun's natural point of aim intact.

If you run a Glock 20 or 21 for duty, sport shooting, or backcountry carry, the USW-G20 adds a dimension of control and confidence without requiring you to maintain a separate rifle. It's the kind of force-multiplier that appeals to shooters who value flexibility and don't want to compromise on either platform.

Key Features

• Folds in under one second—quick transition between pistol and carbine configuration
• Fits Glock 20 and Glock 21 (Gen 3–5 with standard rail)
• Compatible with 10 mm Auto and .45 ACP calibers
• Works with your original Glock open sights as backup
• Supports optional red dot optics for modern shooting setup

Specifications

Frequently Asked Questions

What Glock models does this conversion kit fit?

The USW-G20 is designed for Glock 20 and Glock 21 pistols in generations 3 through 5, as long as they have a standard Glock rail. Check that your frame has the rail under the trigger guard.

Can I use my red dot sight with this kit?

The conversion kit supports optional red dot optics mounting, though the supplied facts note that Glock MOS (Modular Optics System) mounts may present compatibility challenges. We recommend confirming your specific optic's footprint with our sales team before purchase.

How fast can I deploy or stow the stock?

The folding stock deploys or folds in under a second, allowing rapid transitions between pistol-length shooting and carbine configuration without any tools or adjustments.

Does this kit require modifications to my pistol?

No. The USW-G20 uses your Glock's existing rail system and does not require permanent modifications to your firearm. Installation is straightforward, and you can remove the kit if needed.