What Is the Knight’s Armament QDC System? A Suppressor Mount Overview

The Knight’s Armament QDC (Quick Disconnect Coupler) system is the successor to the legacy Gate Latch mount found on suppressors such as the NT4. Designed to offer more secure lockup and easier operation, the QDC system was initially issued to MIL/LE users in the early 2010s and later became available to the commercial market around 2015. The QDC interface remains proprietary to Knight’s Armament and is only found on KAC suppressors.

The system functions by sliding the suppressor over a QDC-compatible muzzle device and twisting it until fully seated. While simple externally, the system uses a set of internal ceramic ball bearings arranged in a circular pattern, which interface with machined sockets on the muzzle device. A V-shaped notch aligns the suppressor to an index pin, and rotating the outer locking collar cams the bearings into place, securing the suppressor with a solid, repeatable lockup.

Suppressor-to-muzzle device compatibility is caliber dependent. While the mounting mechanism is functionally identical, the 7.62 variant is physically larger and not cross-compatible with the 5.56 version. Each caliber-specific suppressor must be paired with the appropriately sized QDC muzzle device. Always verify with an alignment rod before use.

Notable suppressors that feature the QDC mounting system include:

• 5.56 QDC
  
  

• 5.56 QDC CQB
  
  

• 7.62 QDC
  
  

• 7.62 QDC CQB
  
  

• 5.56 QDC CRS PRT
  
  

• 5.56 QDC MCQ PRT
  
  

• 7.62 QDC CRS PRG
  
  

• 7.62 QDC CQB PRG
  
  

• 7.62 PRS-1