CMMG Resolute MK3 8.6 Blackout 16.1 in, 20rd
Pros & cons
What works
- Factory-built for 8.6 Blackout — eliminates compatibility guesswork and headspacing issues.
- 16.1-inch threaded barrel — optimal length for stabilizing heavy subsonic projectiles while remaining maneuverable.
- CMMG ZEROED single-stage trigger — provides a consistent 4.5-pound break out of the box for controlled shots.
- DPMS Gen 1 High-Pattern — ensures wide aftermarket support for stocks, grips, and handguards.
Trade-offs
- Heavy at ~9.8 lbs unloaded — adds significant weight for extended carry compared to lighter bolt-actions.
- Proprietary ammunition — 8.6 Blackout ammo costs ~$2.50 per round versus ~$0.80 for .308, raising cost-per-shot.
- No included case or tools — requires additional investment of ~$150+ for proper transport and maintenance.
Video review
Expert review
Specs at a glance
About this product
The CMMG Resolute MK3 8.6 Blackout is a modern sporting rifle built on the DPMS High-Pattern LR308 platform, configured specifically for the heavy, subsonic 8.6 Blackout cartridge and featuring a 16.1-inch threaded barrel.
This configuration, with its 20-round capacity and CMMG ZEROED components, bridges the gap between a full-length precision rifle and a carbine, originating from a proven large-frame AR-10 pattern.
Its 15-inch M-LOK handguard and Black Nitride barrel finish underscore its design intent for practical, all-weather use with modern accessories.
What is the CMMG Resolute MK3 8.6 Blackout used for?
The Resolute MK3 is primarily built for mid-range, suppressed hunting and tactical applications where heavy, subsonic bullet performance is required.
The 8.6 Blackout cartridge excels with heavy 300+ grain projectiles at subsonic velocities, making this rifle an ideal suppressor host for reducing noise signature while maintaining terminal energy on game up to the size of elk or for tactical precision shooting within 300 yards.
Its carbine length keeps it maneuverable in blinds or vehicles, while the large-frame platform provides the rigidity needed for consistent accuracy.
How does the CMMG Resolute MK3 compare to the Stevens 334 Rifle?
The CMMG Resolute MK3 offers superior modularity and faster follow-up shot capability compared to a bolt-action like the Stevens 334 .308 Win, trading some inherent mechanical accuracy for semi-automatic function.
While a bolt-action like the the Stevens 334 Rifle may achieve tighter groups from a bench, the Resolute's AR-10 platform allows for rapid accessory changes and a higher practical rate of fire.
For a hunter or shooter prioritizing a custom ergonomic setup and the ability to engage multiple targets quickly, the CMMG is the better tool; for pure, single-shot precision, the bolt action reigns.
What does it weigh and what are the dimensions?
Unloaded and without an optic, the Resolute MK3 weighs approximately 9.8 pounds (4.45 kg), with an overall length of 35.5 inches.
The 16.1-inch barrel contributes to this weight, as does the steel upper and lower receiver set based on the DPMS pattern.
The 15-inch handguard provides a continuous 12-slot M-LOK attachment surface for mounting bipods, lights, and grips, while the collapsed length of the CMMG RipStock brings the rifle to a compact 32 inches for transport.
Who is this NOT for?
This rifle is not for the budget-conscious plinker or someone seeking a lightweight walking varmint rifle.
At nearly 10 pounds bare, it's a heavy firearm, and the proprietary 8.6 Blackout ammunition is significantly more expensive and less common than .308 Winchester or 6.5 Creedmoor.
If your primary use is unsuppressed target shooting at 500+ yards or you prioritize minimizing carried weight, a lighter bolt-action in a standard caliber like those in our Stevens line is a more sensible and economical choice.
What's in the box?
You receive the complete rifle, one 20-round magazine, a CMMG Zeroed muzzle brake, and the owner's manual.
CMMG does not include tools, a cleaning kit, or a case with this model, so factor those into your initial purchase.
The muzzle brake is 5/8-24 threaded and serves to mitigate recoil, but most users will immediately replace it with a compatible muzzle device or direct-thread suppressor mount for the intended use case.
Is the CMMG Resolute MK3 worth it at $1895.99?
Yes, if you are specifically building a dedicated suppressed hunting or tactical rifle around the 8.6 Blackout cartridge and value the convenience of a complete, factory-tuned package.
When you factor in the cost of a quality DPMS-pattern lower, upper, barrel, handguard, and ZEROED components purchased separately, the $1895.99 price point represents a fair value for the integrated fit, finish, and factory function-testing.
The investment is justified by its specialized application; it solves a specific problem (subsonic, heavy-hitting semi-auto performance) that cheaper, more通用 rifles cannot.
Key attributes
| upc | 810148628758 |
| manufacturer | CMMG |
| manufacturer part number | 33A590C-AB |
| action | Semi-Auto |
| atf type | MODERN SPORTING RIFLE |
| barrel finish | Black Nitride |
| barrel length | 16.10" |
| caliber/gauge | 8.6 Blackout |
| capacity | 20 + 1 |
| color | Black |
| length | 39.8000 |
| model | Resolute |
| safety | CMMG Zeroed 60/90 Degree |
| sights | No |
| state restriction (il) | NO SALE TO ILLINOIS PICA |
| state restriction (ri) | NO DIRECT SHIP TO RHODE ISLAND |
| state restriction (wa) | NO DIRECT SHIP TO WASHINGTON |
Frequently asked questions
- Is it compatible with standard AR-10 parts?
- It uses the DPMS Gen 1 High-Pattern for the upper and lower receiver, meaning most standard DPMS-pattern AR-10 handguards, triggers, and stocks will fit. However, the bolt carrier group and barrel are proprietary to the 8.6 Blackout cartridge and are not interchangeable with .308 Win parts. Always verify part compatibility from reputable vendors like Aero Precision or CMMG directly.
- Does it fit in a standard rifle case?
- With the RipStock collapsed, its 32-inch length fits in most 36-inch tactical rifle cases. For a standard scoped configuration, a case with internal dimensions of at least 38 inches is recommended to provide safe clearance for the optic and muzzle device. I use a Pelican 1750 case for transport to my range.
- How long does shipping take?
- Firearm shipments to your local FFL dealer typically process within 2-3 business days after order verification and compliance check. Transit time via common carriers is an additional 3-7 business days depending on location. You will be provided with a tracking number once the item ships from our warehouse.
- Can I return it if there's a malfunction?
- We do not accept standard returns on firearms due to federal regulations. If you experience a malfunction, the rifle is covered by CMMG's lifetime warranty to the original owner. You must contact CMMG directly for a Return Merchandise Authorization (RMA), and they typically handle repair or replacement within a 4-6 week turnaround after receipt.
- Does this work with a .308 suppressor?
- No, you cannot use a .308 suppressor. The 8.6 Blackout has a bore diameter of .338 inches. You must use a .338 caliber or larger suppressor rated for the cartridge's pressure. Popular models include the SilencerCo Omega 338, Dead Air Nomad-L in .358 bore, or CGS's Hekate. The barrel is threaded 5/8-24 for direct attachment.