MAT-9K™ Blowback Upper Receiver Gray

Our compact MAT-9 just got smaller with the release of our MAT-9K variants. A five inch barrel reduces its profile for even tighter spaces.

This NEXT Generation blowback 9mm AR upper receiver is bufferless and monolithic (self-contained)  for lower receivers and almost all 9mm magazines. (Ships January 1st)


Add this to cart and begin your next build! Our products are built with a lifetime Warranty.




This upper receiver is side-folding compatible and features Matador Arms® patent-pending EZTS™ “Easy Take-down System” with no tools required to break down the upper for maintenance and cleaning.  The 9mm upper is machined for maximum weight reduction, slim profile, and compatibility with bolt catches and lower receivers. The upper is also built with a tapered multi-material 4-piece trunnion system to maintain mechanical accuracy and durability. This is the shorter version with a five inch barrel.

The MAT-9™  9mm AR upper is compatible with AR-9 Lower receivers in any double-stack magazine configuration:

  • Glock ®
  • Sig Sauer ®
  • Colt® Stick Magazines
  • HK® MP5™
  • CZ ® Evo Scorpion™

With an AR-15 Lower Receiver it requires our Mag-X™ magazine conversion kit or equivalent type product such as Endomags.


Some Additional Key Features:

  • Non-reciprocating steel charging handle (ambidexterous)
  • 4140 Nitrided steel bolt and action parts
  • 6061-T6 anodized upper receiver
  • 4150 Lightweight Nitrided Barrel, 5” long, 1:10 twist, 1/2×28 threads
  • NATO 1913 Spec top rail
  • 1 Mlok slot (both sides, bottom)
  • Compatible with LRBHO (Last Round Bolt Hold Open) lower receiver
  • Ready to run with a Suppressor right out of the box!

Additional information

Weight 3.0 lbs
Dimensions 12 × 4 × 4 in
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