Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard Review

Let’s Talk About Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard

The Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard is a complete upper receiver designed for AR-15 platform rifles chambered in .300 AAC Blackout. Radical Firearms promises a MIL-STD compatible upper, ready to drop onto any standard lower receiver, boasting a 10.5-inch HBAR barrel, a pistol-length gas system, and their 9-inch MHR (M-Lok Hybrid Rail) handguard. This upper assembly aims to provide a versatile and accurate platform for both novice and experienced shooters looking to build or upgrade their AR-15.

I’d been searching for a compact and reliable upper assembly for a dedicated home defense build in .300 Blackout, prioritizing maneuverability and the ability to effectively use a suppressor. I needed something shorter than my existing 16-inch 5.56 upper but with enough rail space for accessories. I was particularly interested in the .300 Blackout cartridge for its subsonic capabilities when paired with a suppressor, making it ideal for minimizing noise in close-quarters situations.

Upon unboxing, the Radical Firearms upper assembly presented a solid first impression. The black Type III anodized finish appeared even and durable, and the MHR handguard felt comfortable and provided ample grip. While the overall weight felt substantial, it wasn’t unwieldy and seemed appropriate for the components used.

I was considering a similar upper from Aero Precision and a complete upper from Palmetto State Armory. Ultimately, I chose the Radical Firearms option due to its aggressive price point and the unique look of the MHR handguard. The hybrid rail system offered both M-Lok slots for accessory attachment and a smooth top surface that I found aesthetically pleasing.

My initial reaction was one of cautious optimism. The price made me slightly skeptical, but the components appeared well-made, and I was eager to see how it performed on the range. The potential for a budget-friendly .300 Blackout build was certainly exciting.

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Real-World Testing: Putting Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard to the Test

First Use Experience

The initial range trip took place at my local outdoor shooting range. The weather was clear and mild, around 70 degrees Fahrenheit, providing ideal shooting conditions. I mounted the Radical Firearms upper onto a standard AR-15 lower receiver, attached a red dot sight, and prepared to zero the optic.

The first few rounds were promising, with consistent cycling and relatively manageable recoil, even without a muzzle device beyond the included A2 flash hider. However, I experienced a few failures to feed within the first 50 rounds, which I initially attributed to potentially under-gassed ammunition. The failures seemed more prevalent with some cheaper, bulk-packed .300 Blackout ammunition.

Despite the initial hiccups, the upper was relatively easy to use, though I did notice the handguard became noticeably warm after extended firing. The M-Lok slots made it easy to attach accessories, but the smooth top rail section got hot enough to be uncomfortable to touch without gloves. The included A2 flash hider did little to mitigate muzzle flash.

Extended Use & Reliability

After several range trips and approximately 500 rounds fired, the Radical Firearms upper assembly’s reliability improved considerably. I switched to using primarily higher-quality ammunition, such as Hornady Black and S&B, and the frequency of malfunctions decreased dramatically. The upper seemed to “break-in” over time.

The finish has held up well with minimal signs of wear, though the A2 flash hider has started to show some carbon buildup. Cleaning is straightforward, requiring standard AR-15 maintenance procedures. The bore cleans easily, and the MHR handguard is easy to wipe down.

Compared to my previous experiences with other AR-15 uppers, the Radical Firearms offering performs adequately but doesn’t necessarily stand out. While accurate and now largely reliable with quality ammunition, it lacks the refined feel and consistent performance of higher-end options like those from Daniel Defense or Bravo Company Manufacturing. It is certainly a good value for the price, especially if you prioritize a budget-friendly build.

Breaking Down the Features of Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard

Specifications

• Caliber: .300 AAC Blackout – This caliber is designed for optimal performance in short-barreled rifles and is known for its versatility in both supersonic and subsonic applications, particularly when suppressed.
• Barrel Length: 10.5 inches – The shorter barrel length makes this upper ideal for close-quarters combat (CQB) scenarios and increases maneuverability.
• Barrel Profile: HBAR (Heavy Barrel) – The heavy barrel profile is intended to improve accuracy by reducing barrel flex and heat buildup during rapid fire.
• Gas System Length: Pistol Length – A pistol-length gas system is standard for short-barreled .300 Blackout rifles, providing the necessary dwell time for reliable cycling.
• Barrel Twist Rate: 1-8 Twist – This twist rate is well-suited for stabilizing a wide range of .300 Blackout bullet weights, from lighter supersonic rounds to heavier subsonic loads.
• Threads per Inch: 5/8×24 – This is the standard thread pitch for .300 Blackout barrels, allowing for compatibility with a wide variety of muzzle devices and suppressors.
• Handguard Type: Free-Float – A free-float handguard enhances accuracy by preventing pressure on the barrel, ensuring consistent harmonics.
• Muzzle Device: A2 Flash Hider – The A2 flash hider is a basic muzzle device that reduces flash signature but offers minimal recoil reduction or muzzle rise compensation.
• Finish: Type III Anodized – Type III anodizing provides a durable and corrosion-resistant finish to the aluminum components.
• Color: Black – A standard black finish allows for easy integration with most AR-15 lowers.
• Gun Model: AR-15 – Designed to be compatible with any standard AR-15 lower receiver.
• Condition: New – The upper assembly is brand new, ensuring all components are within factory specifications.
• Fabric/Material: Forged 7075-T6 Aluminum – Forged 7075-T6 aluminum is a high-strength alloy commonly used in AR-15 receivers and handguards for its durability.
• Gas Block Journal Size-Diameter: .750 in – The .750-inch gas block journal is a standard size, allowing for a wide selection of aftermarket gas blocks.
• Handguard Length: 9 inches – The 9-inch handguard provides ample rail space for mounting accessories while maintaining a compact overall length.
• Handguard Style: Hybrid Rail – The hybrid rail combines M-Lok slots for accessory attachment with a smooth top surface for a comfortable grip.
• Gun Rail: M-LOK – M-LOK slots allow for direct attachment of M-LOK compatible accessories, providing a secure and lightweight mounting solution.
• Gun Type: Rifle – Designed for use with AR-15 rifles.
• Barrel Material: 4140 Chrome Moly Vanadium – 4140 Chrome Moly Vanadium steel is a durable barrel material known for its good balance of hardness, wear resistance, and machinability.
• Magazine Included: No – The upper assembly does not include a magazine.

Performance & Functionality

The Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard performs adequately, providing acceptable accuracy and reliability with quality ammunition. It’s suitable for close-quarters engagements and general range use.

The strengths lie in its compact size, affordability, and M-Lok compatibility. The weaknesses include initial reliability issues with lower-quality ammunition, a basic flash hider, and a handguard that can become excessively hot during sustained fire. While not a top-tier performer, it offers a solid value proposition for budget-conscious builders.

It mostly meets expectations, given its price point. It’s not going to compete with high-end uppers, but it provides a functional and reasonably accurate platform for .300 Blackout.

Design & Ergonomics

The build quality is decent, with a solid feel and a durable finish. The weight is manageable, and the MHR handguard offers a comfortable grip.

There’s a slight learning curve in terms of ammunition selection. It’s critical to use high-quality ammunition for reliable cycling.

Durability & Maintenance

The Type III anodized finish appears durable and should last for years with proper care. The upper is easy to maintain, requiring standard AR-15 cleaning procedures.

Accessories and Customization Options

The upper assembly is compatible with a wide range of AR-15 accessories, including red dot sights, scopes, lights, lasers, and vertical grips. The M-Lok slots on the MHR handguard provide ample mounting options for these accessories.

The standard 5/8×24 threads allow for easy replacement of the A2 flash hider with other muzzle devices or suppressors. The .750-inch gas block journal allows for aftermarket gas block upgrades.

Pros and Cons of Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard

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Who Should Buy Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard?

Perfect for budget-conscious AR-15 builders looking to get into the .300 Blackout platform, those prioritizing a compact and maneuverable rifle for home defense or CQB, and individuals who appreciate the versatility of the M-Lok handguard system for accessory mounting.

Those who prioritize absolute reliability with all types of ammunition, require minimal handguard heat during sustained fire, or demand top-tier accuracy should consider other options.

A must-have accessory would be a quality red dot sight or optic, a weapon light, and potentially a suppressor for those looking to maximize the .300 Blackout’s subsonic capabilities. A more effective muzzle device than the included A2 flash hider is also recommended.

Conclusion on Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard

The Radical Firearms 10.5in 300 Upper Assembly with 9in MHR, M-Lok Hybrid Rail Handguard offers a solid value proposition for those seeking an affordable entry point into the .300 Blackout AR-15 platform. While it has some limitations, such as ammunition sensitivity and handguard heat, its compact size, M-Lok compatibility, and overall build quality make it a worthwhile option for budget-minded builders.

The price is justified, considering the features and performance it offers. It’s not a high-end product, but it provides a functional and reasonably accurate platform for the .300 Blackout cartridge.

I would recommend it to those who understand its limitations and are willing to invest in quality ammunition. It’s a great option for a budget-friendly home defense build or a compact range toy. If you’re looking for a reliable and affordable .300 Blackout upper, give the Radical Firearms offering a try; just remember to feed it good ammo!