The Faxon ARAK-21 Complete Upper in 7.62×39 (brand part number URSSB762) is a gas-piston-driven upper receiver assembly built for shooters who want AK-caliber power with AR-pattern ergonomics. The billet aluminum upper receiver runs on a piston system rather than direct impingement, keeping the action cleaner and reducing carrier heat compared to a standard AR gas system. It ships with a 16-inch nitride-finished steel barrel cut with a 1:8 twist for 7.62×39, an adjustable gas system to fine-tune reliability across ammo types, an M4-style quad rail, ambidextrous safety and charging handle controls, and Faxon’s MuzzLok muzzle device. The whole assembly is made in the USA and weighs 5.5 pounds, and at 16 inches the barrel clears the federal rifle-length minimum with no NFA paperwork required.

Key Specifications

• Chambered in 7.62x39mm.
• Barrel length of 16 inches, clearing the federal rifle minimum.
• Twist rate of 1:8.
• Barrel is steel with a nitride finish.
• Runs a gas-piston operating system instead of direct impingement.
• Upper receiver is billet aluminum.
• Features an M4-style quad rail.
• Includes ambidextrous safety and charging handle controls.
• Gas system is adjustable for different ammo and suppressor use.
• Weighs 5.5 pounds and is made in the USA.

Frequently Asked Questions

Does this include a lower receiver? No, this is a complete upper only; it requires a compatible AR-pattern lower to build a complete rifle.

Is this a direct impingement or piston system? It’s gas-piston operated, which runs cleaner than a direct impingement system.

Is a 16-inch barrel legal without NFA paperwork? Yes, 16 inches clears the federal rifle minimum, so no SBR paperwork is required.

Buy the Faxon ARAK-21 Complete Upper

Add AK-caliber punch to your AR-pattern build with a piston system that runs cleaner than direct impingement. Order this ARAK-21 upper from Faxon Firearms through our AR15 uppers lineup, and our Lubbock, Texas team will get your order ready to ship as soon as it’s available.