Knights Armament M4QD Flash Hider Suppressor Adapter for QDSS-NT4, 5.56mm, 1/2"-28 Thread, Steel Matte

The Knights Armament M4QD flash hider suppressor adapter bridges flash control and suppressor mounting on your 5.56mm rifle. Built as a quick-detach platform for Knights Armament's QDSS-NT4 sound suppressor, this steel adapter lets you keep your rifle nimble in the field without sacrificing modularity. Whether you're running suppressed precision work at the range or need the ability to swap between unsuppressed and suppressed configurations, the M4QD gives you the flexibility to do both without changing your muzzle device.

The 1/2"-28 thread and matte steel construction keep things straightforward—no exotic finishes, just reliable hardware that pairs seamlessly with Knights Armament's suppressor ecosystem. The included 7-piece shim kit means you can dial in barrel harmonics and suppress runout, a detail that matters if you care about consistent downrange performance.

If you're building or upgrading an AR-platform rifle in 5.56 and already own a QDSS-NT4 (or plan to), this adapter consolidates your muzzle solution into one piece. It's the kind of purpose-built component that appeals to shooters who want suppression capability without cobbling together incompatible parts.

Key Features

• Quick-detach platform designed specifically for QDSS-NT4 suppressors
• Doubles as a flash suppressor for unsuppressed shooting
• 1/2"-28 thread fits standard 5.56mm AR barrels
• 7-piece shim kit included for barrel harmonics tuning
• Steel construction with matte finish
• Modular design—swap suppressor on and off without tools

Specifications

Frequently Asked Questions

Will this M4QD adapter work with my QDSS-NT4 suppressor?

Yes. The M4QD is designed as the quick-detach mounting platform for Knights Armament's QDSS-NT4 sound suppressor. They're built to pair together.

What thread size do I need for my barrel?

This adapter features a 1/2"-28 thread, the standard for 5.56mm AR-pattern rifles. Confirm your barrel is threaded 1/2"-28 before purchase.

Can I use this as a flash hider without a suppressor?

Yes. The M4QD functions as a flash suppressor on its own, giving you flash control whether or not you attach a suppressor. When you're ready to run suppressed, the QDSS-NT4 quick-detaches onto the same mounting point.

What's in the box with the M4QD?

The adapter comes complete with a 7-piece shim kit, which allows you to adjust barrel harmonics and reduce runout for optimal performance.