Enhance your next AR9 build with this complete upper assembly from KAK Industry, expertly engineered to pair seamlessly with AR9 lowers. Chambered in 9mm, this upper features a rugged 4" barrel and a compact 5.5" M-LOK free-float handguard, delivering excellent modularity, balance, and durability—perfect for pistol-caliber carbine configurations.
This upper ships fully assembled and includes a bolt carrier group, charging handle, forward assist, and dust cover—everything you need, ready to mount right out of the box.
Whether you're building a pistol or carbine, this upper offers the reliability, performance, and precise fitment you expect—all backed by KAK Industry’s uncompromising commitment to quality.
No guesswork. No hassle. Just performance you can count on.
Upper
- Barrel Length- 4”
- Barrel Material- 41V50 Button Rifled Barrel
- Chamber 9MM NATO
- Twist Rate 1:10
- Muzzle Device- KAK Flashcan 1/2-36
- Gas System- Blowback
- Upper Receiver- Forged 7075 T6 Aluminum, Precision Machined to M16/M4 Spec
- Handguard- 5.5”, High Quality 6061 T6 Material Mlok with Proprietary Clamping System and Heavy-Duty Barrel Nut
- Charging Handle- Milspec with Enhanced Large Billet Latch
- BCG
- One piece BCG
- Auto Profile Carrier Machined from Aircraft/ Bearing Quality 8620 Steel, Properly Heat Treated, Ground to Perfection, BlackNitride Finish by H&M
- Firing pin is machined from 8740, precision ground, and chrome plated
- One Piece Billet Fully Machined Enhanced Extractor, Phosphate coated for Increased reliability and corrosion resistance
- S7 tool steel ejector and extractor retaining pin
- 4130 Gas Key, nitride, precision staked using our hydraulic staking machine
- Carrier key screws- Grade 8, Properly Heat Treated and staked
All KAK complete upper receivers are test fired for feed and function using commercially loaded ammunition
Please note: KAK Industry 9mm uppers do not support last round bolt hold open (LRBHO) functionality when used with our AR9 lowers.
