CMMG Resolute MK4 .338 ARC 16.1in 10rd Armor Black
Specs at a glance
About this product
The CMMG Resolute MK4 .338 ARC 16.1in 10rd Armor Black is a carbine-length semi-automatic rifle that brings big-bore .338 ARC ballistic performance to an AR-platform chassis. It ships with CMMG ZEROED components and the adjustable RipStock for a compact, controllable package. The EML 15 handguard provides M-LOK attachment points at 3, 6, and 9 o'clock and a trimmed top section for a slim profile. The platform maintains AR15 parts compatibility where possible, including bolt commonality with 6.5 Grendel.
| Manufacturer | CMMG |
|---|---|
| Model | Resolute MK4 |
| Material | 7075-T6 aluminum upper and lower receivers, 4140 steel barrel (per manufacturer specs) |
| Compatibility | AR-15 lower parts, triggers, stocks, and grips; bolt commonality with 6.5 Grendel |
| Finish | Armor Black anodized |
| Weight | 6.8 lbs (per manufacturer specs) |
| Condition | New |
Key Features
- .338 ARC Chambering — WHY IT MATTERS: This large-bore cartridge delivers heavy-hitting terminal ballistics out to 600 yards, making it ideal for hunting medium game or defensive use without the recoil of a full-power .308.
- 16.1-Inch Barrel with CMMG ZEROED Components — WHY IT MATTERS: The barrel length balances velocity and maneuverability, while ZEROED parts (handguard, gas block, and muzzle device) are timed and aligned at the factory so you spend less time dialing in and more time shooting.
- Adjustable RipStock — WHY IT MATTERS: This stock lets you fine-tune length of pull and cheek height on the fly, so the rifle fits you whether you're wearing a light shirt or heavy winter gear.
- EML 15 Handguard with M-LOK — WHY IT MATTERS: With slots at 3, 6, and 9 o'clock, you can mount lights, lasers, or grips exactly where you need them, and the slim profile keeps your support hand comfortable during long sessions.
- AR-15 Parts Commonality — WHY IT MATTERS: You can swap triggers, grips, and stocks from your existing AR-15, so upgrading or repairing this rifle is straightforward and affordable.
Who It's For
This rifle is for the shooter who wants big-bore performance in a familiar AR platform. It's a great fit for hunters looking to take deer or hogs with a suppressed-savvy cartridge, or for shooters who want a home-defense rifle with serious stopping power. New gun owners will appreciate the adjustable stock and easy-to-use controls, while experienced builders will like the parts compatibility.
Pros & Cons
Pros: Accurate .338 ARC cartridge with moderate recoil, fully adjustable stock, slim handguard for easy handling, compatible with standard AR-15 parts, factory-timed components reduce setup hassle.
Cons: .338 ARC ammunition is still relatively new and can be harder to find compared to 5.56 NATO or .300 Blackout. You'll want to stock up on your preferred load before heading to the range.
Comparison: CMMG Resolute MK4 vs. Zev Technologies vs. Geissele
| Feature | CMMG Resolute MK4 .338 ARC | Zev Technologies AR-15 (5.56) | Geissele Super Duty (5.56) |
|---|---|---|---|
| Caliber | .338 ARC | 5.56 NATO | 5.56 NATO |
| Barrel Length | 16.1 inches | 16 inches | 16 inches |
| Handguard | EML 15 M-LOK | Zev M-LOK | Geissele MK16 M-LOK |
| Stock | Adjustable RipStock | Standard buffer tube (stock not included) | Geissele Super 42 buffer system |
| Weight | 6.8 lbs | 6.5 lbs | 7.0 lbs |
| MSRP | $1,537.60 | $1,800 | $1,950 |
The CMMG offers a larger bore for better terminal performance at a lower price than both competitors. Zev and Geissele are excellent choices for 5.56, but if you want a heavy-hitting round in a lightweight package, the Resolute is the better buy.
FAQ
What is the effective range of the .338 ARC in this rifle?
With a 16.1-inch barrel, the .338 ARC is effective for accurate shots out to 600 yards on medium-sized game. Subsonic loads stay quiet with a suppressor and are useful for shorter ranges under 200 yards.
Can I use standard AR-15 magazines with this rifle?
Yes. The Resolute MK4 accepts standard AR-15 magazines, though you may need to use magazines specifically designed for .338 ARC or 6.5 Grendel for best feeding reliability. The included 10-round magazine works out of the box.
Is the barrel threaded for a suppressor?
Yes. The barrel comes threaded 5/8x24 TPI, which is common for .30-caliber suppressors. The CMMG ZEROED muzzle device can be removed and replaced with your suppressor mount.
Does this rifle require special tools for assembly or maintenance?
No. Because it uses standard AR-15 lower parts and a standard barrel nut, you can disassemble and maintain it with common AR-15 tools like a barrel wrench and vice block.
Ready to Order
This rifle is in stock and ready to ship. We offer nationwide delivery to all 50 states (please check local laws). Orders ship within 1-2 business days, and you have 30 days to return if it's not the right fit. Your checkout is secure.
- ✅ Nationwide delivery (all 50 states)
- ✅ Ships 1-2 business days
- ✅ 30-day returns
- ✅ Secure checkout
Browse more in our Semi Auto Rifles category, or check out AR-15 Parts for upgrades. For more big-bore options, see our Hunting Rifles.
Last updated: April 2026