First Thoughts on the CMMG Resolute MK4 300 Blackout 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Charging
The CMMG Resolute MK4 300 Blackout upper receiver group represents a solid foundation for any AR-platform build centered around the versatile 300 Blackout cartridge. Sporting a 16.10″ barrel and finished in an attractive Midnight Bronze, this upper promises both aesthetic appeal and functional performance. Its M-LOK free-float handguard offers ample space for accessories, allowing for customization to suit individual needs. However, it’s important to note that this is just the upper receiver; it requires a bolt carrier group (BCG) and charging handle to be fully operational.
I had been looking for a dedicated 300 Blackout upper receiver to pair with a lower I had assembled for subsonic suppressed shooting. The CMMG name carries weight in the AR world, known for producing reliable components. The Midnight Bronze finish also caught my eye; it offered a welcome change from the standard black and FDE options typically available.
Upon receiving the CMMG Resolute MK4, I was immediately impressed by the fit and finish. The Midnight Bronze anodizing was consistently applied, and the handguard felt incredibly sturdy. The free-float design gave the upper a rigid, quality feel. Compared to a similar upper from a less reputable brand, the CMMG felt like a clear upgrade in terms of overall construction and attention to detail.
My initial reaction was excitement. This upper group seemed like a worthwhile investment to complete my 300 Blackout build and I was eager to see how it performed at the range.
Real-World Testing: Putting CMMG Resolute MK4 300 Blackout 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Charging to the Test
First Use Experience
I tested the CMMG Resolute MK4 at my local outdoor range, focusing on both supersonic and subsonic ammunition. The weather was mild and sunny, ideal for a relaxed shooting session. Pairing the upper with a quality BCG and charging handle, the assembly process was straightforward, and the upper mated seamlessly with my existing lower receiver. The upper receiver was installed on an AR-15 lower with a crisp trigger pull.
The CMMG performed admirably, cycling both types of ammunition smoothly. There were no malfunctions or feeding issues during the first 100 rounds. Accuracy was also quite impressive, with consistent groupings at 50 and 100 yards.
Extended Use & Reliability
After several months of use and over 500 rounds fired, the CMMG Resolute MK4 continues to perform reliably. The finish has held up well, showing minimal signs of wear despite regular use and cleaning. Cleaning the upper is relatively simple; standard AR cleaning procedures apply.
Compared to previous experiences with less expensive uppers, the CMMG has proven to be a worthwhile upgrade. The improved accuracy and reliability have made it a go-to choice for my 300 Blackout needs. The durability of the finish is far superior to a budget-priced upper I previously owned.
Breaking Down the Features of CMMG Resolute MK4 300 Blackout 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Charging
Specifications
Caliber: The CMMG Resolute MK4 is chambered in 300 Blackout, a versatile cartridge known for its effectiveness in both supersonic and subsonic applications. This caliber choice is ideal for those seeking a capable round for home defense, hunting, or suppressed shooting.
Barrel Length: It features a 16.10″ barrel, a common and practical length for the 300 Blackout. This length provides a good balance between maneuverability and ballistic performance.
Receiver Finish: The Midnight Bronze receiver finish offers a unique and attractive aesthetic. This finish provides enhanced corrosion resistance, extending the upper’s lifespan.
Handguard: Equipped with an M-LOK free-float handguard, the upper offers ample space for mounting accessories. The free-float design enhances accuracy by preventing the handguard from contacting the barrel.
These specifications translate to a reliable and accurate platform. The M-LOK handguard is essential for mounting accessories to customize the rifle to user preference.
Performance & Functionality
The CMMG Resolute MK4 performs exceptionally well, delivering consistent accuracy and reliable cycling. Its 16.1″ barrel provides sufficient velocity for both supersonic and subsonic rounds, maintaining effectiveness at various distances. The combination of quality construction and precise chambering ensures reliable feeding and extraction, minimizing the risk of malfunctions.
Its primary strength lies in its reliability and consistent performance. The absence of a BCG and charging handle necessitates an additional purchase, which could be seen as a drawback for some buyers.
The CMMG Resolute MK4 has exceeded my expectations in terms of performance and reliability. It delivers consistent and accurate results, making it a worthwhile investment for any AR enthusiast.
Design & Ergonomics
The build quality of the CMMG Resolute MK4 is exceptional. The use of high-quality materials and precise machining ensures a robust and durable platform. The Midnight Bronze finish not only enhances the aesthetic appeal but also provides added protection against wear and corrosion.
The M-LOK handguard offers a comfortable and secure grip, allowing for easy attachment of accessories. There is no learning curve, it seamlessly integrates with any standard AR-15 lower receiver.
Durability & Maintenance
The CMMG Resolute MK4 is built to last. The robust construction and durable finish ensure it can withstand the rigors of regular use.
Standard AR-15 maintenance procedures apply, making it easy to clean and maintain. With proper care, this upper receiver should provide years of reliable service.
Accessories and Customization Options
The CMMG Resolute MK4 itself does not come with any included accessories. However, its M-LOK handguard provides ample space for mounting a wide range of accessories, including optics, lights, lasers, and foregrips.
The upper receiver is compatible with most AR-15 accessories, allowing for extensive customization. You can swap out the muzzle device for a suppressor or compensator, and the handguard can be customized with various M-LOK compatible attachments.
Pros and Cons of CMMG Resolute MK4 300 Blackout 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Charging
Pros
- Exceptional Accuracy: The free-float handguard and quality barrel contribute to outstanding accuracy.
- Reliable Performance: The upper cycles both supersonic and subsonic ammunition smoothly, ensuring reliable operation.
- Durable Construction: The use of high-quality materials and a durable finish ensures long-lasting performance.
- M-LOK Handguard: Provides ample space for mounting accessories, allowing for extensive customization.
- Aesthetically Pleasing Finish: The Midnight Bronze finish offers a unique and attractive look.
Cons
- BCG and Charging Handle Not Included: Requires separate purchase of a BCG and charging handle.
- Price: While offering excellent value, the initial cost may be higher compared to some budget options.
Who Should Buy CMMG Resolute MK4 300 Blackout 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Charging?
The CMMG Resolute MK4 300 Blackout is perfect for AR-15 enthusiasts looking to build a high-quality and reliable 300 Blackout rifle. It caters particularly well to those interested in hunting, home defense, or suppressed shooting. The rifle is also a great fit for competitive shooters.
Those on a very tight budget or those looking for a complete, ready-to-shoot upper receiver group might want to consider other options. A must-have accessory is a quality BCG and charging handle to complete the build.
Conclusion on CMMG Resolute MK4 300 Blackout 16.10″, Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Charging
The CMMG Resolute MK4 300 Blackout upper receiver group is a high-quality component that delivers exceptional performance and reliability. Its durable construction, accurate barrel, and versatile M-LOK handguard make it a worthwhile investment for any AR-15 enthusiast. The price is justified by the superior build quality and performance compared to cheaper alternatives.
I would personally recommend the CMMG Resolute MK4 to anyone looking to build a reliable and accurate 300 Blackout rifle. Upgrade your AR platform today!