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FAXON ARAK-21® 16" 5.56 NATO COMPLETE UPPER IN TUNGSTEN® CERAKOTE (URSSB556SSW) - SHIPS FROM SPORTS SOUTH
FAXON FIREARMS
$1,032.99
Trusted Distribution Partner
This product ships directly from one of Faxon's authorized distribution partners. It may arrive separately from Faxon-shipped items in your order, with its own tracking. Learn more ›
Shipping & returns — Trusted Distribution Partner items
When will my order ship?
Trusted Distribution Partner items typically ship within 1–3 business days from our partner's warehouse, separate from any Faxon-fulfilled items in your order. Transit times depend on the carrier and destination.
Will tracking come from Faxon?
Yes — you'll receive a tracking notification from Faxon Firearms when your partner-shipped item leaves the warehouse. If your order also contains Faxon-fulfilled items, you'll receive separate tracking for each shipment.
Can I combine this with other Faxon items in one shipment?
No. Items marked Trusted Distribution Partner ship from a different warehouse than Faxon-fulfilled items and will arrive separately. Each shipment has its own tracking and may arrive on different days.
How do returns work for partner-shipped items?
Returns for Trusted Distribution Partner items are handled by Faxon Customer Service rather than through our standard self-service portal, so we can coordinate the return with our partner on your behalf.
To start a return, contact us at customerservice@faxonfirearms.com or submit a request through our support form and select “Refund / Return.”
Is this product authentic and covered by warranty?
Yes. All Trusted Distribution Partner products are sourced from authorized distributors and are covered by the original manufacturer's warranty. Faxon stands behind every product sold on faxonfirearms.com.
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FAXON FIREARMS
FAXON ARAK-21® 16" 5.56 NATO COMPLETE UPPER IN TUNGSTEN® CERAKOTE (URSSB556SSW) - SHIPS FROM SPORTS SOUTH
Sports South Exclusive. Limited-production tungsten Cerakote® finish on the upper receiver and lower handguard plate. Same patented ARAK-21® platform, same performance—a finish you won’t find anywhere else.
The ARAK-21® is the weapon system that started Faxon Firearms—born from a kitchen-table sketch by founder Bob Faxon who believed no rifle should force shooters to choose between AR modularity and AK-style reliability. What came out of that idea is a patented, billet-machined monolithic upper receiver (U.S. Patent No. 9,032,860) that drops onto any standard AR-15 lower and fundamentally changes how the rifle operates.
No buffer tube. No gas tube. No forward assist. The ARAK-21® replaces the entire conventional AR gas system with a long-stroke piston with dual spring-loaded operating rods that cycle inline with the barrel. The bolt carrier rides on hardened QPQ steel rails—not aluminum—eliminating metal-on-aluminum wear and delivering AK-pattern reliability with AR-15 ergonomics, accuracy, and modularity. A non-reciprocating forward charging handle, reversible bolt, dual ejection ports, and an adjustable gas valve make it fully ambidextrous and suppressor-tunable out of the box.
This 16″ complete upper in 5.56 NATO ships with a 1:8 twist barrel and a Faxon MuzzLok® ported brake. Drop it on your existing AR-15 lower, charge, and fire. No permanent modifications, no proprietary lower, no buffer tube or spring required. And because the ARAK-21® uses a tool-less barrel swap system, you can convert this upper to 7.62x39mm in the field with a Faxon caliber conversion kit—no armorer, no bench, no tools.
Exclusive Sports South
Patented U.S. Pat. 9,032,860
No Buffer Tube Required
2 Calibers Tool-Less Swap
16″ • 1:8 5.56 NATO
Tungsten Cerakote®: Sports South Exclusive Finish
This limited-production ARAK-21® wears a tungsten Cerakote® finish on the upper receiver and lower handguard plate—a warm, medium-gray ceramic coating that sets it apart from the standard black nitride version. Cerakote® is an industry-leading ceramic-based coating that provides enhanced corrosion resistance, chemical resistance, and abrasion resistance beyond what traditional finishes offer. Available exclusively through Sports South authorized dealers—when this production run is gone, it’s gone.
How the ARAK-21® Works
A standard AR-15 cycles by tapping gas from the barrel, routing it through a gas tube, and slamming it back into the bolt carrier group inside the upper receiver. The buffer spring—housed inside the buffer tube behind the lower receiver—absorbs that energy and returns the bolt forward. It works, but it ties the entire system to a fixed-length buffer tube and routes hot, carbon-laden gas directly into the action.
The ARAK-21® eliminates all of that. Faxon’s patented system uses a long-stroke piston with dual spring-loaded operating rods that run alongside the barrel inside the monolithic upper receiver and forearm housing. Gas taps from the barrel into a piston cup, which drives the operating rods rearward against their own springs—contained entirely within the upper receiver. The bolt carrier rides on hardened QPQ steel rails built into the monolithic housing, so you never have steel cycling against bare aluminum. The system fires without ever sending gas into the receiver and without needing a buffer tube, buffer spring, or buffer retainer from the lower. A detented 5-position gas regulator—adjustable with the tip of a cartridge—lets you tune the system from reduced gas for suppressed fire all the way up to adverse-condition settings, with no tools required.
No Buffer Tube — Folding Stock Ready
The entire recoil system lives inside the upper. Your lower receiver’s buffer tube is freed up—run a folding stock, a side-folder, a PDW brace, or any non-standard stock configuration that a conventional AR-15 can’t accommodate. The rifle fires and cycles with the stock folded.
Cleaner, Cooler Action
Gas never enters the receiver. The piston system vents gas at the front of the handguard, keeping the bolt carrier group, trigger, and lower receiver significantly cleaner than a direct-impingement AR-15. Less carbon in the action means less maintenance and more reliable cycling—especially suppressed or in adverse conditions.
Fully Ambidextrous
The ARAK-21® features a non-reciprocating forward charging handle that swaps from left to right side in the field without tools, a reversible bolt with dual ejection ports and shell deflector, and is compatible with ambidextrous AR-15 lower controls. Left-handed or right-handed—no compromise, no adapters, no armorer.
Tool-Less Barrel Swap
The ARAK-21®’s barrel assembly unit (BAU) integrates the barrel, trunnion, adjustable gas system, and piston components into a single drop-in module. Swap from 5.56 NATO to 7.62x39mm in the field—change calibers, barrel lengths, or both. One upper, multiple missions. Caliber conversion kits available separately.
Engineered Details
Specifications
One Upper, Multiple Calibers
The ARAK-21® upper accepts any ARAK-21® barrel assembly unit (BAU). Each BAU integrates the barrel, trunnion, adjustable gas system, and piston components into a single drop-in module—everything needed to change calibers. Pop the existing BAU out, drop a new one in, and you’re shooting a different caliber. No tools, no headspace adjustment, no armorer required. For a full caliber change, Faxon’s conversion kit adds the matching bolt, giving you everything needed to reconfigure in minutes.
Shop Caliber Conversion Kits ($450) → • Shop Barrel Assembly Units ($325) →
Frequently Asked Questions
What makes the ARAK-21® different from a standard AR-15 upper?
The ARAK-21® replaces the entire conventional AR gas system with a patented long-stroke piston and dual reciprocating operating rods (U.S. Patent No. 9,032,860 B2). The recoil system is self-contained in the billet monolithic upper—no buffer tube, buffer spring, or buffer retainer is needed from the lower receiver. Gas never enters the receiver, the action runs significantly cleaner, and the barrel assembly swaps out without tools for caliber conversion. It also features a non-reciprocating forward charging handle, reversible bolt with dual ejection ports, and an adjustable gas valve.
Will this fit my existing AR-15 lower?
Yes. The ARAK-21® uses standard AR-15 takedown and pivot pins. It drops onto any mil-spec AR-15 lower receiver with no permanent modifications. Use your existing trigger, grip, and stock. You can swap between an ARAK-21® upper and a standard AR upper on the same lower anytime.
Do I still need a buffer tube?
No. The ARAK-21®’s dual-spring operating system is entirely self-contained in the upper receiver. You can run a folding stock, side-folder, PDW brace, or any non-standard stock configuration. The rifle fires and cycles with the stock folded. If you already have a buffer tube on your lower for your stock, it simply stays in place—the ARAK-21® just doesn’t use it.
Can I change calibers on this upper?
Yes. The ARAK-21® uses a tool-less barrel assembly unit (BAU) system. Each BAU integrates the barrel, trunnion, adjustable gas system, and piston components into a single drop-in module. Remove the current 5.56 BAU and insert a 7.62x39mm BAU—no tools, no armorer, no bench required. Caliber conversion kits (BAU + bolt) and standalone barrel assembly units are available separately in both 12.5″ and 16″ lengths.
What is the tungsten Cerakote® finish?
Cerakote® is an industry-leading ceramic-based coating that provides enhanced corrosion resistance, chemical resistance, and abrasion resistance. The tungsten colorway is a warm, medium-gray finish applied to the upper receiver and lower handguard plate on this limited-production variant. This finish is exclusive to Sports South authorized dealers.
What is the charging handle setup?
The ARAK-21® uses a non-reciprocating forward charging handle mounted on the left side of the forearm by default. It does not move during firing. The handle is tool-less reversible—press it forward past its detent, pull straight out, reorient, and press back in on the opposite side. The swap can be done in the field in seconds with no tools or additional parts. There is no rear charging handle like a standard AR-15.
Can left-handed shooters use the ARAK-21®?
Absolutely. The ARAK-21® was designed for full ambidextrous operation. The bolt is reversible for left- or right-side ejection through dual ejection ports, and the non-reciprocating charging handle can be mounted on either side. Pair it with an ambi lower receiver and you have a truly left-hand-friendly rifle.
Is this upper suppressor compatible?
Yes. The 16″ barrel ships with a MuzzLok® ported brake on 1/2x28 threads, compatible with any standard .223/5.56 suppressor or muzzle device. The detented 5-position gas regulator lets you dial down to the “reduced” setting for suppressed fire—just rotate with a cartridge tip. The piston design also keeps gas out of the receiver, reducing blowback compared to direct-impingement setups when shooting suppressed.
What does “monolithic upper” mean?
The ARAK-21®’s upper receiver and forearm housing are machined from a single billet of aluminum rather than assembled from separate receiver and handguard components. This monolithic construction eliminates handguard loosening, provides superior barrel support for optic alignment, and creates an uninterrupted full-length Picatinny rail across the entire top of the system.
Where is the ARAK-21® made?
Every ARAK-21® is designed and manufactured by Faxon Firearms in Greater Cincinnati, OH, USA. Faxon is an ISO 9001:2015 certified manufacturer and federally licensed FFL. The ARAK-21® operating system is protected by U.S. Patent No. 9,032,860 B2, with design patent USD708,693 S.
Expand your ARAK-21®. Add calibers with a Caliber Conversion Kit ($450) or a standalone Barrel Assembly Unit ($325). Want the full integrated system? Check out the ARAK-21® XRS Complete Firearms with a matched Faxon billet lower. The ARAK-21®’s piston design and adjustable gas regulator make it an excellent suppressor host—browse Faxon suppressors →
The ARAK-21® Upper Assembly is not itself considered a firearm under federal law or the National Firearms Act. Mounting the ARAK-21® Upper Assembly to some lower receivers may create a firearm subject to the NFA or local restrictions. It is the owner’s responsibility to comply with all federal, state, and local laws.
ARAK-21®, HARMONIX®, and MuzzLok® are registered trademarks of Faxon Firearms. Cerakote® is a registered trademark of NIC Industries, Inc. All other trademarks are property of their respective owners. The ARAK-21® operating system is protected by U.S. Patent No. 9,032,860 B2. Design protected by U.S. Design Patent USD708,693 S.
- receiver finish:
- Tungsten Cerakote®
- action:
- 5.56 NATO
- barrel length:
- 16"
- Fulfillment Source:
- Trusted Distribution Partner
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