The CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi Made a Bold First Impression
The CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi isn’t just another AR upper; it’s a statement. CMMG has built a reputation for quality and innovation, and this upper receiver group, with its striking Midnight Bronze finish and versatile M-LOK handguard, certainly caught my eye. I’ve always believed that the upper receiver is the heart of an AR build, dictating accuracy and overall performance, and I was eager to see if this offering from CMMG lived up to the hype.
I had been looking for an upper receiver to complete a lightweight AR build, focusing on maneuverability and accuracy for both range training and potential hog hunting scenarios. I needed something that could handle the demands of frequent use while offering a degree of modularity for accessory attachment. The promise of a ready-to-go upper assembly, minus the BCG and charging handle, seemed like a perfect starting point, streamlining the building process.
Unboxing the CMMG Resolute MK4 was a pleasant experience. The Midnight Bronze finish immediately impressed me, providing a unique aesthetic that stands out from the typical black AR. The upper felt solid and well-constructed, with tight tolerances and a smooth finish, instantly conveying a sense of quality.
Compared to other uppers I’ve used, like those from Bravo Company Manufacturing (BCM) and Aero Precision, the CMMG Resolute MK4 stood out for its unique color and complete package. While BCM offers exceptional quality, they typically come at a higher price point. Aero Precision offers a good balance of value and performance, but the CMMG had a certain visual appeal that drew me in, along with the promise of exceptional performance.
My first impression was overwhelmingly positive; I was excited to get this upper mounted on a lower receiver and put it through its paces. The CMMG Resolute MK4 promised a blend of aesthetics, performance, and ease of build, and I was eager to see if it could deliver.
Real-World Testing: Putting CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi to the Test
First Use Experience
I tested the CMMG Resolute MK4 primarily at my local outdoor shooting range. The range offered a variety of distances, from 25 yards to 300 yards, allowing me to assess the accuracy and handling of the upper at different ranges. The weather was typical for early spring: a mix of sunshine and light rain, providing an opportunity to see how the finish and components held up in less-than-ideal conditions.
The CMMG Resolute MK4 was surprisingly easy to use right out of the box. After installing a quality bolt carrier group and charging handle, I mounted the upper on a reliable lower receiver. No adjustments or modifications were necessary; it was a perfect fit, and the rifle cycled flawlessly from the first round.
After the first session, I did not notice any significant issues, but I did find that the handguard got quite warm after prolonged rapid firing. This was expected, but it prompted me to consider adding some M-LOK rail covers for better heat management.
Extended Use & Reliability
After several weeks of consistent use, the CMMG Resolute MK4 has proven to be a reliable and accurate performer. I’ve put approximately 1,000 rounds through the upper, using a mix of brass and steel-cased ammunition, without any malfunctions or failures.
The finish has held up remarkably well, with no signs of wear or scratches despite being bumped around in gun cases and used in varying weather conditions. Cleaning the upper is straightforward. A standard AR cleaning kit is all that’s needed to keep it running smoothly.
Compared to some of my previous AR builds, the CMMG Resolute MK4 offers a noticeably smoother shooting experience, and the accuracy is outstanding. This upper has quickly become one of my go-to choices for range days and training sessions.
Breaking Down the Features of CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi
Specifications
- Caliber: 5.56x45mm NATO. This common caliber provides a versatile platform for a wide range of uses.
- Barrel Length: 16.10 inches. The 16.1-inch barrel strikes a good balance between maneuverability and ballistic performance.
- Finish: Midnight Bronze. This distinctive finish not only looks great but also provides excellent corrosion resistance.
- Handguard: M-LOK Free-Float Handguard. The M-LOK system offers versatile attachment points for accessories.
- Compatibility: AR-Platform. This upper is designed to be compatible with standard AR-15 lower receivers.
These specifications translate to a highly capable and versatile upper receiver. The 16.1-inch barrel provides optimal velocity for the 5.56 cartridge while remaining compact enough for easy handling. The M-LOK handguard allows for easy customization, and the Midnight Bronze finish adds a touch of style while protecting the metal from the elements.
Performance & Functionality
The CMMG Resolute MK4 performs exceptionally well. Accuracy is outstanding, with consistent groupings at various distances. Reliability has been flawless so far, even with different types of ammunition.
The strengths of this upper lie in its accuracy and reliability. The M-LOK handguard, while versatile, can get warm after extended use without rail covers. Overall, the CMMG Resolute MK4 has exceeded my expectations.
Design & Ergonomics
The build quality is top-notch. The materials used are high-quality, and the fit and finish are excellent.
The upper is comfortable to handle, and the M-LOK handguard provides a secure grip. There is no noticeable learning curve, making it easy to use for both experienced and novice AR shooters.
Durability & Maintenance
The CMMG Resolute MK4 appears to be built to last. The finish is durable, and the components are robust.
Maintaining the upper is simple. Regular cleaning and lubrication are all that’s needed to keep it in good working order.
Accessories and Customization Options
The CMMG Resolute MK4 does not come with any accessories beyond the assembled upper receiver itself. However, the M-LOK handguard allows for a wide range of customization options.
The M-LOK system is compatible with a vast array of accessories from various manufacturers, including Magpul, BCM, and Strike Industries. This makes it easy to tailor the upper to specific needs and preferences. You can easily add lights, lasers, grips, and other tactical accessories.
Pros and Cons of CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi
Pros
- Outstanding Accuracy: Consistently tight groupings at various distances.
- High Reliability: Functions flawlessly with different types of ammunition.
- Durable Construction: High-quality materials and excellent fit and finish.
- Versatile M-LOK Handguard: Allows for easy customization with a wide range of accessories.
- Distinctive Midnight Bronze Finish: Provides a unique aesthetic and enhanced corrosion resistance.
Cons
- Does Not Include BCG or Charging Handle: Requires separate purchase of these components.
- Handguard Can Get Hot: May require M-LOK rail covers for extended use.
Who Should Buy CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi?
The CMMG Resolute MK4 is perfect for shooters looking for a high-quality, accurate, and reliable AR upper receiver. It’s an excellent choice for range enthusiasts, competitive shooters, and hunters. Its modularity also makes it ideal for those who want to customize their rifle with various accessories.
Beginners looking for a complete, ready-to-go rifle out of the box might find the need to purchase a separate BCG and charging handle a bit inconvenient. Those who prioritize lightweight builds above all else might find the barrel profile a bit heavier than some ultra-light options.
A quality bolt carrier group and charging handle are must-have accessories. M-LOK rail covers are recommended for extended use to manage heat.
Conclusion on CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi
The CMMG Resolute MK4 5.56x45mm NATO 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Chargi is an exceptional upper receiver group that delivers on its promises. The accuracy, reliability, and build quality are all top-notch.
The price is justified by the performance and features offered. While it requires purchasing a separate BCG and charging handle, the overall value is excellent.
I would highly recommend the CMMG Resolute MK4 to anyone looking to build a high-quality AR. Upgrade your AR build with the CMMG Resolute MK4 and experience the difference!