The FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG is a complete, ready-to-run upper receiver assembly built for shooters who need a reliable, accurate, and low-maintenance platform. Chambered in 5.56 NATO with a 16-inch barrel and a compensator, this upper combines a side-charging action with a long-stroke gas piston system to keep carbon and fouling out of the receiver. It drops onto any standard AR-15 lower with no special tools or modifications required.
| Manufacturer | Faxon Firearms |
|---|---|
| Model | URSSB556SSW ARAK21 |
| Material | 7075-T6 aluminum receiver, 4150 CMV barrel (per manufacturer specs) |
| Compatibility | Standard AR-15 lower receivers (M4, A2, mil-spec, billet) |
| Finish | Type III hard coat anodized black |
| Weight | 4.8 lbs (complete upper, per manufacturer specs) |
| Condition | New |
Key Features
- Side Charging Handle — WHY IT MATTERS: Lets you charge the rifle without breaking your cheek weld, keeping your eye on target for faster follow-up shots in field conditions.
- Long-Stroke Gas Piston System — WHY IT MATTERS: Runs cleaner than direct impingement, reduces carbon buildup in the receiver, and cycles reliably with a wide range of ammunition—including steel-case.
- 16-Inch Barrel with Compensator — WHY IT MATTERS: Balances maneuverability with ballistic performance, and the integrated compensator cuts muzzle rise so you stay on target during rapid fire.
- Free-Float M-LOK Handguard — WHY IT MATTERS: Keeps barrel harmonics consistent for better accuracy and gives you a solid mounting platform for lights, lasers, and grips.
- Tool-Less Handguard Removal — WHY IT MATTERS: You can swap handguards or clean the piston system without a wrench—saves time in the field or at the bench.
Who It’s For
This upper is built for ranchers, rural workers, and utility shooters who need a rifle that runs in dust, mud, and rain without constant cleaning. If you want a side-charging, piston-driven upper that drops onto your existing lower with no hassle, this is it. It’s also a solid pick for left-handed shooters who prefer a non-reciprocating charging handle on the left side.
Pros & Cons
- Pro: Piston system keeps the bolt carrier group and receiver clean—less maintenance means more time shooting.
- Pro: Side-charging handle is ambidextrous-friendly and works with scopes or red dots that sit low over the receiver.
- Con: The compensator is loud and throws a noticeable blast to the sides—not ideal for indoor ranges or tight cover without ear pro.
Comparison
| Feature | Faxon ARAK21 Upper | Zev Technologies AR Upper | Geissele Super Duty Upper |
|---|---|---|---|
| Operating System | Long-stroke gas piston | Direct impingement | Direct impingement |
| Charging System | Side-charging (non-reciprocating) | Rear charging (standard) | Rear charging (standard) |
| Barrel Length | 16 inches | 14.5 inches (pinned) | 16 inches |
| Weight (complete upper) | 4.8 lbs | 3.9 lbs | 4.2 lbs |
| MSRP | $1,163.84 | $1,250 | $1,100 |
FAQ
Does this upper fit any AR-15 lower?
Yes. The FAXON URSSB556SSW ARAK21 upper is designed to drop onto any mil-spec AR-15 lower receiver. No adapter plates or modifications are needed. Just pin it on and you’re good to go.
Is the charging handle ambidextrous?
The side-charging handle is located on the left side of the upper and can be operated by either hand. It’s non-reciprocating, so it stays still while the bolt cycles—no risk of catching on gear or smacking your fingers.
What kind of accuracy can I expect from the 16-inch barrel?
Per Faxon specs, the 4150 CMV barrel is button-rifled and typically holds sub-2 MOA groups with quality match ammunition. With standard M193 or M855 ball ammo, expect 2.5 to 3 MOA—good enough for coyotes, hogs, and steel out to 400 yards.
Does the compensator work with a suppressor?
No. The integral compensator is not designed for suppressor mounting. If you want to run a can, you’ll need to swap the muzzle device or use a different upper. The FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG is built for unsuppressed use.
What gas piston system does this use?
It uses a long-stroke gas piston system, similar to an AK-47 or AR-18. The piston rod is attached to the bolt carrier and moves with it, reducing carbon blowback into the receiver. According to Faxon specs, this design runs cleaner than direct impingement and requires less frequent lubrication.
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Last updated: April 2026
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FFL Transfer & Firearms Laws for FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG
All firearms, including the FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG, must be shipped to a licensed Federal Firearms License (FFL) dealer. You will be required to complete a background check and any necessary paperwork before taking possession.
How It Works
- Place your order online.
- Provide your preferred FFL dealer information.
- We ship the firearm directly to your FFL.
- You complete the background check and pickup at the FFL.
Legal Compliance
We comply with all federal and state firearm laws. It is your responsibility to ensure the FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG is legal in your state. Some states may have restrictions on certain firearm models or features.
Helpful Resources
Need assistance? Contact our Miami store for help with FFL transfers and firearm compliance.
Frequently Asked Questions About This Product
Why buy FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG from Miami Shooters Supply?
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Where can I buy FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG?
You can purchase this item directly on our website and have it shipped to your local FFL dealer. You can also visit us in-store in Miami, Florida.
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FFL Transfer & Firearms Laws
All firearms, including the FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG, must be shipped to a licensed Federal Firearms License (FFL) dealer. A background check and any required local paperwork must be completed before you can take possession.
How It Works
- Place your order online.
- Send us your preferred local FFL dealer info.
- We ship the firearm to your FFL after verification.
- Complete background check and pick up from your dealer.
Legal Compliance
We comply with all U.S. firearm laws. It is your responsibility to ensure the FAXON URSSB556SSW ARAK21 16 556 COMP UPPER TNG is legal in your state. Some states (e.g. CA, NY, NJ) have restrictions on magazine size or certain features.
Helpful Links
Need help? Contact our team — we’ll guide you through selecting a compliant firearm and the FFL transfer process.
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