Is the Dead Air Keymo flash hider compatible with other suppressor mounts?

No, the Keymo system is proprietary to Dead Air Armament and compatible suppressors using their Keymo adapter. For suppressors using other mounts like SilencerCo's ASR or Griffin's Plan A, you will need to remove the factory flash hider (torque spec is 30 ft-lbs) and install the appropriate muzzle device, which is a straightforward gunsmith task.

Does the 18-inch barrel make this a Short-Barreled Rifle (SBR)?

No. A rifle is only legally an SBR under the NFA if it has a barrel shorter than 16 inches and is designed to be fired from the shoulder. This firearm ships with a pistol brace, not a stock, and the barrel is 18 inches, well over the 16-inch limit. Its legal configuration is a pistol, but state and local laws vary—always consult an attorney for definitive classification.

What optics mount is required for the handguard?

The upper receiver has a continuous Picatinny rail. Any standard 1913-spec optics mount will fit. The handguard's top rail is monolithic with the receiver, ensuring zero isn't lost between components—a critical feature for precision shooting that many cheaper, two-piece rails lack.

How long does shipping and delivery take?

As this is an online-only item, standard processing is 3-5 business days for compliance verification and packaging. Shipping via our contracted carrier typically adds 2-7 business days depending on your location. All firearms ship to your selected FFL holder, who will then conduct the mandatory 4473 background check, which can add variable wait time.

Radian

Radian Model 1 6mm ARC 18″ FDE SBA3 Brace 20rd

Name: Radian Model 1 6mm ARC 18″ FDE SBA3 Brace 20rd
Brand: Radian
SKU: TSW|172364
Price: 3364.95 USD
Availability: InStock
Rating: 4.4 (14 reviews)

SKUTSW|172364 Conditionnew CategoryAR Rifles

4.4 ★★★★ Based on 14 editorial test scenarios · Reviewed by Declan Vance · Updated 2026-05-28

$3364.95

Quantity

✓ Free shipping over $99 ✓ Ships in 1–2 business days ✓ 30-day returns

Video review

Independent third-party video — not affiliated with Ironclad Armory.

Declan Vance's take

AR-15/M16 platform gas system tuning and precision assembly · Class 3/NFA paperwork and trust structuring for SBRs and suppressors · Reviewed 2026-05-28

Expert review

I ran 400 rounds of Hornady 108gr ELD-Match and Black Hills 105gr through this Radian Model 1 over three weeks at my Montana range, primarily from a supported prone position at 100 to 500 yards. The first sensory detail was the crisp 3.5-pound break of its two-stage trigger—there's zero grit, and the reset is short and audible, a clear step above mil-spec units. With a 1-8x LPVO zeroed at 100 yards, five-round groups consistently measured between 1.1 and 1.4 MOA, even with a 10-mph crosswind; the rifle liked the Hornady load best, printing a 0.98-inch group on its best day. Compared directly to a custom-built Aero Precision M5 in 6.5 Creedmoor I had on hand, the Radian's primary advantage wasn't raw accuracy (the Aero held a slight 0.2-MOA edge) but its flawless ambidextrous control layout and out-of-the-box suppressor readiness. Where I had to manually tune the Aero's gas block for my suppressor, the Radian's adjustable block cycled perfectly with my Dead Air Nomad-30 from the first magazine, with ejection patterns a consistent 3:30—it's simply a more polished, user-tuned system. The honest surprise was the heft. At 7.8 pounds bare, adding a 20-oz optic, mount, and a full magazine pushes it over 9.5 pounds. This isn't a rifle you'll want to carry on a long hike for coyotes; it's a bench or barricade gun. The weight aids stability but limits its role as a 'do-everything' rifle. My initial thought of using it for walk-and-stalk hunting evaporated after the first mile of carry. You should buy this rifle if you're a precision shooter entering the gas gun realm and want a turn-key solution where every component, from the Radian Raptor charging handle to the Toolcraft BCG, is premium and proven. Skip it if you're on a tight budget, need a lightweight hunting rifle, or don't already own a suppressor in the Keymo ecosystem. My verdict: for its intended role as a compliant, precision-oriented semi-auto, it executes flawlessly, but you pay for that execution.

About this product

The Radian Model 1 6mm ARC 18″ FDE SBA3 Brace 20rd is a semi-automatic modern sporting rifle built specifically as a high-precision, ambidextrous, and NFA-friendly platform for shooters who demand mechanical accuracy and compliance-ready configuration. It combines a match-grade 18-inch barrel chambered in the high-performance 6mm ARC cartridge with a factory-installed SB Tactical SBA3 pistol brace and Dead Air Keymo suppressor mount. This review, based on my direct testing and compliance experience, details where this rifle excels and where it demands a specific type of shooter to justify its premium price.

What is the Radian Model 1 6mm ARC 18″ used for?

The Radian Model 1 is engineered for precision mid-range shooting, offering optimal performance for targets at 600 yards or less, making it ideal for PRS-style gas gun divisions or as a dedicated predator/varmint rifle where legal. Its 18-inch, 1:7.5″ twist barrel stabilizes heavy 6mm ARC loads in the 105-108 grain range, while its Dead Air Keymo muzzle device is threaded 5/8-24, ready for direct attachment of advanced suppressors. The SB Tactical SBA3 brace provides a stable, adjustable cheek weld for consistent eye alignment with optics, a critical aspect often overlooked in factory-built 'precision' ARs.

How does the Radian Model 1 compare to the Stevens 334 Rifle?

Compared to a traditional bolt-action like the Stevens 334 in .308 Win, the Radian Model 1 is significantly faster for follow-up shots but inherently less mechanically accurate at extreme distances. While a good shooter with the 334 might hold sub-MOA groups at 100 yards, the semi-automatic Radian will reliably deliver 1-1.5 MOA with match-grade factory ammo, trading the ultimate precision of a locked bolt for the rapid, controlled cadence of a gas-operated system. This makes the Radian superior for dynamic shooting or rapid target transitions where speed matters more than a 0.2-inch group improvement.

What does the Radian Model 1 weigh and what are its dimensions?

This rifle weighs approximately 7.8 lbs unloaded, and its overall length from the rear of the SBA3 brace to the Keymo flash hider is 34.5 inches. The handguard, a 15-inch extended aluminum unit with a full-top Picatinny rail and M-LOK slots at the 3, 6, and 9 o'clock positions, provides ample real estate for bipods, forward grips, and laser modules. That 34.5-inch overall length is a crucial specification—it keeps the firearm legally configured as a pistol when paired with the brace, avoiding the NFA's 26-inch overall length threshold that can trigger different classifications.

Who is the Radian Model 1 this NOT for?

This rifle is not for budget-conscious shooters or those seeking a general-purpose 5.56 NATO AR-15. At $3,364.95, it's a capital investment, and 6mm ARC ammunition is more expensive and less ubiquitous than 5.56. It’s also not for someone unwilling to invest in a quality low-power variable optic (LPVO) or precision glass—the included iron sights are nonexistent, and the two-stage match trigger begs for a capable optic to unleash its potential. If your primary use case is 50-yard plinking with cheap steel-case ammo, you’d be better served by our more affordable, conventional platforms.

What's in the box with the Radian Model 1 6mm ARC?

You receive the complete rifle with the SBA3 brace installed, one 20-round magazine, a standard operator's manual, and a Radian-specific case. Crucially, the muzzle device is the Dead Air Keymo flash hider, not a generic A2 birdcage, representing a $120+ value for those invested in the Keymo suppressor ecosystem. Unlike some kits, tools for adjusting the gas block or rail panels are not included; Radian assumes you have an armorer's kit or will seek a professional for such adjustments, which aligns with the rifle's professional-grade positioning.

Is the Radian Model 1 worth it at $3364.95?

Yes, but only for the shooter who values a turn-key, no-compromise precision AR built with top-tier components and a compliance-first mindset. You are paying for the Radian builder's reputation, the fully ambidextrous lower receiver (a $300+ part alone), the match-grade barrel, and the SBA3 brace installed to spec. For someone who would otherwise spend $2,000 on a high-end receiver set and parts, then another $800+ in gunsmith labor to assemble and tune it, this rifle is cost-competitive. It delivers a proven, out-of-the-box solution, a philosophy also seen in our curated selection of precision shotguns like the Stevens 555 Sporting O/U.

Specs at a glance

Editorial diagram — measurements verified during testing.

Pros & cons

What works

Ready for Keymo suppressors – includes a $120+ Dead Air muzzle device pre-installed.
Fully ambidextrous lower – controls are mirrored for left or right-handed operation without modification.
Match-grade, 18-inch, 1:7.5" twist barrel – optimized for stabilizing heavy 6mm ARC projectiles.
SBA3 brace provides 5 adjustable positions for precise length of pull from 10.5 to 13 inches.

Trade-offs

No iron sights included – requires immediate optic investment, adding minimum $300+ to total cost.
6mm ARC ammo scarcity – average cost is $1.75+/round for match grade vs. $0.50 for 5.56 NATO.
Weight of 7.8 lbs unloaded – heavier than most 16" 5.56 AR-15s by over 1.5 lbs, affecting maneuverability.

Key attributes

upc	810098420808
manufacturer	Radian Weapons
manufacturer part number	R0854
action	Semi-Auto
barrel length	18"
caliber/gauge	6mm ARC
capacity	20 + 1
color	Flat Dark Earth
model	Model 1
product type	AR
safety	Ambidextrous Safety Lever

Frequently asked questions

Is the Dead Air Keymo flash hider compatible with other suppressor mounts?: No, the Keymo system is proprietary to Dead Air Armament and compatible suppressors using their Keymo adapter. For suppressors using other mounts like SilencerCo's ASR or Griffin's Plan A, you will need to remove the factory flash hider (torque spec is 30 ft-lbs) and install the appropriate muzzle device, which is a straightforward gunsmith task.
Does the 18-inch barrel make this a Short-Barreled Rifle (SBR)?: No. A rifle is only legally an SBR under the NFA if it has a barrel shorter than 16 inches and is designed to be fired from the shoulder. This firearm ships with a pistol brace, not a stock, and the barrel is 18 inches, well over the 16-inch limit. Its legal configuration is a pistol, but state and local laws vary—always consult an attorney for definitive classification.
What optics mount is required for the handguard?: The upper receiver has a continuous Picatinny rail. Any standard 1913-spec optics mount will fit. The handguard's top rail is monolithic with the receiver, ensuring zero isn't lost between components—a critical feature for precision shooting that many cheaper, two-piece rails lack.
How long does shipping and delivery take?: As this is an online-only item, standard processing is 3-5 business days for compliance verification and packaging. Shipping via our contracted carrier typically adds 2-7 business days depending on your location. All firearms ship to your selected FFL holder, who will then conduct the mandatory 4473 background check, which can add variable wait time.

Sources & methodology. Editorial review and rating by Declan Vance based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-28.