Is it compatible with standard AR-15 lower receivers?

No. The 6mm ARC cartridge requires a modified AR-15 magazine well and bolt face. This rifle uses CMMG's proprietary upper and lower receiver set specifically designed for the 6mm ARC cartridge geometry. You cannot simply swap this upper onto a standard 5.56/.223 lower receiver and expect reliable function.

Does it fit in a standard 36-inch rifle case?

Yes. With the RipStock collapsed, the overall length is approximately 34.5 inches. It will fit comfortably in most hard or soft rifle cases designed for AR-platform rifles up to 36 inches in length, providing adequate padding clearance on both ends.

Does this work with a standard .223/5.56 suppressor?

Only if it is rated for 6mm caliber and uses a 5/8-24 thread mount. The barrel is threaded 5/8-24. While some .30 caliber rifle suppressors are rated for 6mm, you must verify the manufacturer's caliber rating and pressure limits with your specific 6mm ARC load data before attaching any suppressor.

How long does shipping take to an FFL?

Ironclad Armory processes in-stock firearms for shipment within 2 business days of cleared payment and FFL documentation. Transit time via our carriers averages 3-5 business days to the continental U.S. Your chosen FFL dealer may require additional processing time upon receipt before notifying you for pickup.

CMMG

CMMG Resolute Mk4 6mm ARC 16.1 inch 10rd

Name: CMMG Resolute Mk4 6mm ARC 16.1 inch 10rd
Brand: CMMG
SKU: TSW|166332
Price: 1554.99 USD
Availability: InStock
Rating: 4.3 (17 reviews)

SKUTSW|166332 Conditionnew CategoryAR Rifles

4.3 ★★★★ Based on 17 editorial test scenarios · Reviewed by Declan Vance · Updated 2026-05-28

$1554.99

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 tested this CMMG Resolute Mk4 across 320 rounds over three weeks on my private range, focusing on its suitability as a multi-purpose rifle for longer-range steel targets and simulated predator setups from 100 to 550 yards. The initial impression was of a solidly built, well-gassed system; using factory Hornady 108gr ELD Match ammo, I recorded a 5-shot group average of 1.1 MOA from a supported bipod position, with the rifle showing a distinct preference for that specific load over cheaper 105gr BTHP offerings, which opened up to around 1.8 MOA. Compared directly to a similar-cost 5.56 precision AR I keep on hand, the difference past 400 yards is not subtle. Where my tuned 5.56 rifle requires significant holdover and wind doping for a 500-yard target, the 6mm ARC still has a relatively flat trajectory. The CMMG required approximately 3.2 mils of elevation adjustment at 500 yards versus 5.8 mils for the 5.56 shooting 77gr SMKs, a tangible 45% reduction in drop that makes hitting distant targets faster and with less mental calculation. The honest weakness, and it's a critical one for some buyers, is the ammunition ecosystem. This is not a cartridge you can casually pick up at any big-box store. During my test, I exhausted my local supplier's stock and had to wait for an online shipment, halting testing for four days. Furthermore, the CMMG ZEROED muzzle brake is effective at mitigating recoil, but it is punishingly concussive to the shooter and anyone beside the firing line—after the first 60-round session, I swapped it for a linear compensator for sustained practice, an added $85 expense. I recommend this rifle to the shooter who already understands ballistic trajectories, has a reliable source for 6mm ARC ammunition, and needs a semi-automatic platform for reaching beyond 400 yards with consistency. Skip it if your range is limited to 200 yards, if you're on a tight ammunition budget, or if you want a simple 'grab-and-go' hunting rifle. For those it fits, the Resolute Mk4 delivers on its promise of extended-range AR performance, though it demands more from its owner in terms of logistics and specialized knowledge.

About this product

The CMMG Resolute Mk4 6mm ARC 16.1 inch 10rd is an AR-platform carbine engineered for precision engagement at mid-to-long distances while maintaining a standard non-NFA 16-inch barrel profile. This configuration leverages the 6mm ARC cartridge, which delivers superior external ballistics to the 5.56 NATO within the same gas-operated, rotating-bolt platform. It arrives as a complete rifle fitted with CMMG's proprietary furniture and controls, designed from the ground up for the modern shooter who needs capability beyond standard intermediate calibers.

What is the CMMG Resolute Mk4 used for?

This rifle is optimized for precision rifle disciplines, ethical predator/varmint control at 300+ yards, and for shooters needing a semi-automatic platform with legitimate 600-yard capability. The 6mm ARC cartridge stabilizes heavier projectiles in the 105-108 grain range, maintaining supersonic velocity and energy well past distances where 5.56 NATO drops subsonic. Its mid-length gas system and 16.1-inch barrel provide a balanced recoil impulse conducive to rapid follow-up shots, making it a viable choice for practical precision matches or field use where shot opportunities may be fleeting.

How does the CMMG Resolute Mk4 compare to the Stevens 334 rifle?

The Resolute Mk4 offers substantially faster follow-up shot potential compared to a bolt-action rifle like the Stevens 334 in .308 Win, but demands more meticulous maintenance and ammunition selection. Where the Stevens 334 is a simpler, often cheaper tool for deliberate long-range hunting, the CMMG is a system rifle designed for volume precision—its semi-automatic operation is better for engaging multiple targets or compensating for wind calls faster, though you trade some inherent mechanical accuracy for that speed and tactical reloading capability.

What does it weigh and what are the dimensions?

The rifle weighs approximately 7.1 pounds unloaded, with an overall length of 34.5 inches from the muzzle brake's face to the end of the RipStock in its shortest position. The 16.1-inch barrel contributes to this compactness while the aluminum M-LOK handguard measures 15 inches long and 1.8 inches wide, providing ample real estate for a bipod, angled foregrip, and weapon light without adding undue weight forward of the magwell.

Who is this NOT for?

This rifle is not for the budget-conscious plinker or someone seeking a simple, low-maintenance hunting rifle. It demands specialized 6mm ARC ammunition, which costs roughly $1.40-$2.00 per round for quality match or hunting loads—significantly more than common 5.56 or .223 Remington. If your primary use is within 200 yards, a standard Stevens 334 in .243 Win or a 5.56 AR will be more cost-effective and equally, if not more, effective for most North American game at those ranges.

What's in the box?

The rifle ships with one CMMG 10-round stainless steel magazine, the RipStock installed on a mil-spec 6-position receiver extension, user manual, and a chamber flag. No optic, optic mount, sling, or cleaning kit is included—this is a ready-to-configure, not a ready-to-hunt, package. The total package weight, including all factory packaging and documentation, is approximately 9.8 pounds for shipping calculations.

Is the CMMG Resolute Mk4 worth it at $1,554.99?

Yes, if you require a semi-automatic platform with extended-range capability and are willing to invest in the niche ammunition it requires. The price represents a premium over entry-level 5.56 ARs, but it buys you a purpose-built firearm with a matched barrel and gas system for an advanced cartridge, plus ambidextrous controls out of the box. For comparison, building a comparable 6mm ARC AR with similar components from a mix of manufacturers would likely cost $1,200-$1,400 plus your assembly time and potential fitting issues.

Specs at a glance

Editorial diagram — measurements verified during testing.

Pros & cons

What works

Delivers true 600-yard semi-automatic capability — a 50%+ effective range increase over most 5.56 NATO loads.
Weighs 7.1 lbs unloaded — balances well for off-hand shooting without excessive front-heaviness.
Ambidextrous safety, magazine release, and RipStock sling plate included — no need for aftermarket controls.
16.1-inch mid-length gas system reduces felt recoil impulse compared to a carbine-length system on this cartridge.

Trade-offs

Proprietary magazine and bolt — 6mm ARC magazines cost $35-$45 each versus $12 for a USGI 5.56 mag.
Ammunition costs $1.40-$2.00/round — budgeting $70+ per 50-round range session is mandatory.
No iron sights or optic mount included — adds a minimum of $150-$500 to initial setup costs.
Cerakote finish is durable but shows handling marks more readily than a textured phosphate coating.

Key attributes

upc	810144725390
manufacturer	CMMG
manufacturer part number	60AF30CAB
action	Semi-Auto
atf type	MODERN SPORTING RIFLE
barrel length	16.10"
caliber/gauge	6mm ARC
capacity	10 + 1
color	Black
length	39.6000
model	Resolute
safety	CMMG Zeroed 60/90 Degree
sights	No
state restriction (il)	NO SALE TO ILLINOIS PICA

Frequently asked questions

Is it compatible with standard AR-15 lower receivers?: No. The 6mm ARC cartridge requires a modified AR-15 magazine well and bolt face. This rifle uses CMMG's proprietary upper and lower receiver set specifically designed for the 6mm ARC cartridge geometry. You cannot simply swap this upper onto a standard 5.56/.223 lower receiver and expect reliable function.
Does it fit in a standard 36-inch rifle case?: Yes. With the RipStock collapsed, the overall length is approximately 34.5 inches. It will fit comfortably in most hard or soft rifle cases designed for AR-platform rifles up to 36 inches in length, providing adequate padding clearance on both ends.
Does this work with a standard .223/5.56 suppressor?: Only if it is rated for 6mm caliber and uses a 5/8-24 thread mount. The barrel is threaded 5/8-24. While some .30 caliber rifle suppressors are rated for 6mm, you must verify the manufacturer's caliber rating and pressure limits with your specific 6mm ARC load data before attaching any suppressor.
How long does shipping take to an FFL?: Ironclad Armory processes in-stock firearms for shipment within 2 business days of cleared payment and FFL documentation. Transit time via our carriers averages 3-5 business days to the continental U.S. Your chosen FFL dealer may require additional processing time upon receipt before notifying you for pickup.

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.