FAXON ION ULTRALIGHT INTEGRAL MUZZLE DEVICE 16" 5.56 AR15 RIFLE
Faxon
$1,600.00
FAXON ION ULTRALIGHT INTEGRAL MUZZLE DEVICE 16" 5.56 AR15 RIFLE
The Faxon ION Ultralight Integral Muzzle Device 16" 5.56 AR15 Rifle is built around one of Faxon's most distinctive engineering innovations—the patented Integral Muzzle Device Pencil Profile Barrel. By machining the barrel and 3-port muzzle brake as a single continuous piece of steel, we eliminate the threaded interface, reduce overall mass, and deliver a permanent, clean muzzle setup that meets the federal 16" minimum barrel length for rifles. The result is a featherweight 4.95-lb AR15 that handles fast, shoots soft, and ships ready for competition or the range.
Part of Faxon's ION Line, this rifle is purpose-built for shooters who prioritize minimum weight and don't need a removable muzzle device. Around the integral barrel, the build pairs the Faxon Enhanced Forged Receiver Set with tensioning screw, the Faxon Gunner Lightweight M16 BCG with Superfinish, a 13" Carbon Fiber M-LOK® Handguard, our multi-position adjustable gas block, and the Faxon Enhanced Match Trigger by Schmid® for crisp, consistent breaks under speed. From the factory, every ION Ultralight ships with a stack of upgrades that would otherwise require a separate parts list and an afternoon at the bench.
Built by an American manufacturer. Faxon Firearms is a family-owned manufacturer founded in 2012 and headquartered in Greater Cincinnati, Ohio. The Faxon family’s manufacturing and engineering roots date back to 1978—producing mission-critical components for aerospace, defense, and industrial programs. That same process control and machining discipline carries directly into our firearms, barrels, receivers, and critical small parts.
Key Features
- Total rifle weight: 4.95 lbs — an ultralight 16" 5.56 AR15 in its class
- Patented 16" 5.56 NATO Integral Pencil Profile Barrel with 3-Port Brake — barrel and brake machined as one continuous piece; meets the federal NFA 16" minimum barrel length requirement for rifles
- Integral 3-Port Muzzle Brake — effective recoil mitigation with no threaded interface or pin-and-weld joint to fail or service
- Faxon Enhanced Forged Receiver Set with tensioning screw — 7075-T6 forged aluminum, Type III hard coat anodize, for a tight upper-to-lower fit
- Faxon Gunner Lightweight M16 BCG with Superfinish for reduced reciprocating mass and smoother cycling
- 13" Carbon Fiber M-LOK® Handguard — high strength at a fraction of the weight of comparable aluminum handguards
- Multi-Position Adjustable Gas Block — tune cycling for ammunition variation and overall reliability
- Faxon Enhanced Match Trigger by Schmid® — crisp, precise pull for confident shot placement under competition or training pace
- Ambidextrous Charging Handle
- Ambidextrous Safety Selector
- MFT Minimalist Stock (or similar ultralight configuration)
- B5 Grip (or similar ergonomic grip)
- Mid-Length Gas System
- Each rifle is individually test-fired and tuned with factory-new 55gr 5.56 NATO ammunition before shipping
Use Cases
- Competition and action shooting: sub-5-lb weight and a 3-port integral brake deliver fast handling, soft recoil, and quick splits—with no muzzle device timing or attachment to ever come loose
- Training and range use: the integral design means one less part to service, and the lightweight platform stays comfortable across long, high round-count days
- Lightweight defensive and patrol applications: a permanent, clean muzzle setup paired with full 16" rifle ballistics in an ultralight package
Who it’s for: shooters who prioritize minimum weight and want a clean, permanent muzzle setup—competitors, instructors, and range shooters who don't need to swap muzzle devices.
Who it’s not for: shooters who want to run a suppressor or change muzzle devices—the integral brake is permanent and cannot be removed. If suppressor compatibility or muzzle device flexibility is a priority, our threaded-muzzle ION variants (FX5516 and FX5516X) are designed for that role.
What’s In This Build (Bill of Materials)
- Receiver Set: Faxon Enhanced Forged AR15 Receiver Set w/ Tensioning Screw — 7075-T6 Forged Aluminum, Type III Hard Coat Anodize
- Barrel: Faxon Patented 16" 5.56 NATO Integral Pencil Profile Barrel with 3-Port Brake (rifled portion + integral brake = 16" total)
- Muzzle Device: Integral 3-Port Brake (machined into the barrel; not removable)
- Handguard: Faxon 13" Carbon Fiber M-LOK® Handguard
- Gas Block: Multi-Position Adjustable Gas Block
- Gas Tube: Mid-Length Stainless Steel
- BCG: Faxon Gunner Lightweight M16 BCG with Superfinish
- Charging Handle: Ambidextrous Charging Handle
- Safety: Ambidextrous Safety Selector
- Trigger: Faxon Enhanced Match Trigger by Schmid®
- Stock: MFT Minimalist Stock (or similar ultralight configuration)
- Grip: B5 Grip (or similar ergonomic grip)
- Buffer: Carbine buffer system tuned for the ION Ultralight gas profile
Explore Related
Warranty
All Faxon Firearms products are backed by our Lifetime Guarantee.
For full warranty terms, service instructions, and exclusions, please visit:
https://faxonfirearms.com/warranty-privacy-terms/
For full warranty terms, service instructions, and exclusions, please visit:
https://faxonfirearms.com/warranty-privacy-terms/
Resources
Click here for product manuals
Shipping Restrictions: This product cannot be shipped to CA, CT, DC, HI, IL, MD, MA, NJ, or NY due to state restrictions on AR-style rifles.
FAQs
What is the patented Integral Muzzle Device Pencil Profile Barrel?▾
It's a Faxon-patented design where the barrel and the 3-port muzzle brake are machined as a single, continuous piece of steel. There's no threaded interface, no pin-and-weld joint, and no separate brake to time or replace. The result is a lighter, cleaner muzzle setup with one fewer point of potential failure or wear—and a permanent, integrated brake that mitigates recoil right out of the box.
Is this a 16" NFA-compliant rifle?▾
Yes. The total barrel length, including the integral 3-port brake portion, measures 16 inches—meeting the federal minimum barrel length requirement for rifles. Because the muzzle device is machined into the barrel rather than threaded or pinned and welded on, the integral assembly is permanent by design.
Can I attach a suppressor to this rifle?▾
The integral muzzle device on this rifle cannot be removed—it's machined into the barrel itself—so direct-thread or quick-detach suppressors that mount to muzzle threads are not compatible with this build. If suppressor compatibility is a primary consideration for your purchase, our threaded-muzzle ION variants (FX5516 and FX5516X) are designed for that role and accept industry-standard 5.56 suppressors and mounts.
Why a pencil profile barrel?▾
Pencil profile barrels offer the best balance of weight and accuracy for general-purpose use. On the ION Ultralight, the pencil profile combined with the integral brake design is the single biggest contributor to the rifle's sub-5-lb weight, while Faxon's process control keeps bore concentricity and harmonics consistent.
Can I shoot both .223 Remington and 5.56 NATO?▾
Yes. The barrel is chambered in 5.56 NATO, which safely supports both 5.56 NATO and .223 Remington ammunition.
Is each rifle test-fired before shipping?▾
Yes. Every ION Ultralight is individually test-fired and gas-tuned with factory-new 55gr 5.56 NATO ammunition before it leaves our facility.
Where is this rifle made?▾
The ION Ultralight is machined and assembled in-house at Faxon Firearms in Greater Cincinnati, Ohio.
What warranty applies?▾
All Faxon Firearms products are backed by our Lifetime Guarantee.
For full warranty terms, service instructions, and exclusions, please visit:
https://faxonfirearms.com/warranty-privacy-terms/
Faxon Lifetime Guarantee. Covers manufacturing and material defects to the original purchaser. Excludes damage from misuse, neglect, non-standard ammunition, or modifications. Register your product at faxonfirearms.com/product-registration to expedite service. For purchases through dealers or distributors, warranty repairs are handled directly by Faxon Firearms; refunds must be processed through the selling entity. Full policy: faxonfirearms.com/warranty-privacy-terms/
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- Caliber:
- 5.56 NATO
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Reviews
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Faxon ION Ultralight 5.56 Rifle
Sweet shooting firearm. If you are an older shooter and the weight of standard 5.56's becomes too much, this is the platform for you. Super light (4.95 pounds), accurate, and just fun to shoot.
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Great rifle
Pros: lightweight and operates perfectly. Cons: it ate my ammo.
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great rifle---but loud!
just as advertised! this thing is SOOO light compared to my other ARs! had an issue with my front takedown pin (the spring)...caused me a real issue...Jesse T. with customer service was amazing! returned all my emails and advised me to send the rifle back...they ended up building me a brand new lower!!! a week later, I was back in business! thanks Jesse! this thing is REALLY loud though...make sure you invest in some good ear protection! :) solid firearm all around so I would definitely recommend!!!
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The best AR-15 I've shot and the star of shoot day
Shoot day is fun for the whole family, but there is always a few of the smaller folks like moms or wives that wish they could enjoy the 223/556 rifles. Now they can. Mothers day ended up with mom advance requesting this as her next/main shooter. Didn't think she'd ever get tired of the hitting the gongs and she's never been more accurate/consistent/fast! Light weight made it so easy for her to hold and shoot. Standing, sitting, bench and the brake made it gentle enough too.... I'll write off all the ammo as a mothers day gift ;)
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FX5500
Fantastic AR. Lighter than you can imagine. Shoots great and groups tight. Very good fit and finish. No complaints here. Thanks Faxon for a great First Responder discount.