Jacob Grey Firearms 5.56 NATO Complete Upper Assembly Review

Getting My Hands on the Jacob Grey Firearms 5.56 NATO Complete Upper Assembly

The AR-15 platform is the Lego set of the firearms world, endlessly customizable and adaptable to almost any role. With countless manufacturers offering every part imaginable, choosing the right components can be overwhelming. My latest quest was to build a compact, reliable, and accurate AR pistol, and the Jacob Grey Firearms 5.56 NATO Complete Upper Assembly immediately caught my eye with its combination of a short barrel and high-quality components.

I’ve always been a proponent of short-barreled rifles and pistols for their maneuverability in tight spaces and ease of transport. The promise of a complete upper assembly, including a bolt carrier group (BCG) and charging handle, sealed the deal.

Unboxing the upper revealed a clean, well-machined unit. The 7075 aluminum upper receiver felt solid, and the 7-sided M-LOK handguard provided a secure and comfortable grip. The hard coat anodized finish appeared durable and evenly applied.

I considered a few other options before settling on the Jacob Grey Firearms upper. Daniel Defense and Bravo Company Manufacturing (BCM) were on my list, but their complete uppers with similar barrel lengths came at a significantly higher price point. The inclusion of the BCG and charging handle with the Jacob Grey Firearms upper made it a more cost-effective choice.

My first impression was one of excitement. The fit and finish were excellent, and the components felt high-quality. I was eager to see how it would perform at the range.

Real-World Testing: Putting Jacob Grey Firearms 5.56 NATO Complete Upper Assembly to the Test

First Use Experience

I took the Jacob Grey Firearms 5.56 NATO Complete Upper Assembly to my local outdoor range for its initial test. I mounted it on a dedicated AR pistol lower receiver with a brace. The weather was clear and mild, providing ideal shooting conditions.

The upper performed flawlessly through the first 200 rounds. There were no failures to feed or extract, and the action cycled smoothly. The pistol-length gas system seemed well-tuned, providing reliable function without excessive recoil.

The only initial issue I noticed was the muzzle flash from the short 7.5-inch barrel. This is to be expected from such a short barrel, but it was more pronounced than with some other similar setups I’ve used.

Extended Use & Reliability

After several months of regular use, the Jacob Grey Firearms 5.56 NATO Complete Upper Assembly has proven to be remarkably reliable. I’ve put approximately 1,000 rounds through it with various types of ammunition, including brass and steel-cased rounds. It consistently cycles without issue.

The hard coat anodized finish has held up well, showing only minor signs of wear around the ejection port. Cleaning is straightforward, and the BCG wipes clean easily. I’ve experienced no malfunctions related to the upper assembly itself.

Compared to a previous budget-built upper I owned, the Jacob Grey Firearms upper is a significant step up in terms of reliability and accuracy. It has become my go-to AR pistol upper for both recreational shooting and home defense.

Breaking Down the Features of Jacob Grey Firearms 5.56 NATO Complete Upper Assembly

Specifications

• Caliber: 5.56x45mm NATO. This is the standard AR-15 caliber, offering a wide range of ammunition options.
• Overall Length: 17 inches. This compact length makes it ideal for maneuverability.
• Barrel Length: 7.5 inches. The short barrel provides extreme compactness, but sacrifices some velocity and increases muzzle flash.
• Barrel Profile: Government. The Government profile is a good balance of weight and rigidity.
• Gas System Length: Carbine Length. This gas system is designed for shorter barrels and provides reliable cycling.
• Barrel Twist Rate: 1-7. This twist rate is ideal for stabilizing heavier bullets, typically 62 grains and above.
• Threads per Inch: 1/2×28. This is the standard thread pitch for 5.56 barrels, allowing for a wide range of muzzle devices.
• Handguard Type: Free-Float. A free-float handguard improves accuracy by not contacting the barrel.
• Muzzle Device: Flash Hider. The included flash hider helps to reduce muzzle flash, but it is not as effective as some aftermarket options.
• Finish: Class III Type 2 Hard Coat Anodized. This finish provides excellent corrosion resistance and durability.
• Fabric/Material: Chrome Moly Vanadium, 7075 T6 Aluminum. These high-quality materials ensure strength and longevity.
• Gas Block Journal Size-Diameter: .750 in. .750 is a standard gas block size allowing for many aftermarket options.
• Handguard Length: 7 in. A 7 inch handguard offers sufficient space for attachments while maintaining a compact profile.
• Handguard Style: Round Rail. A round rail handguard is comfortable and ergonomic to grip.
• Gun Rail: M-LOK. M-LOK provides a lightweight and versatile mounting system for accessories.
• Weight: 56 oz. The weight is reasonable for a complete upper assembly with these features.
• Barrel Material: Chrome Moly. Chrome Moly barrels provide a good balance of accuracy and durability.
• Bolt Carrier Group Included: MIL-SPEC. A MIL-SPEC BCG ensures compatibility and reliability.
• Charging Handle Included: MIL-SPEC. A MIL-SPEC Charging Handle ensures compatibility and reliability.
• Upper Receiver: 7075 Aluminum Upper Receiver A 7075 Aluminum Upper Receiver provides a lightweight and durable platform

Performance & Functionality

The Jacob Grey Firearms 5.56 NATO Complete Upper Assembly performs admirably for its intended purpose: providing a compact and reliable AR pistol platform. Accuracy is acceptable, producing groupings of around 3-4 inches at 50 yards with iron sights. The reliability is excellent, with no malfunctions experienced during testing.

The short barrel does result in a significant increase in muzzle flash and noise, making it less than ideal for prolonged use without hearing protection. The lack of a forward assist is a design choice that might concern some users, but I have not found it to be an issue in practice due to the tight tolerances and reliability.

Overall, the upper meets my expectations for a short-barreled AR pistol upper. It excels in compactness and reliability, making it a great option for home defense or as a truck gun.

Design & Ergonomics

The build quality is excellent, with tight tolerances and a durable finish. The 7075 aluminum upper receiver and M-LOK handguard feel solid and well-made. The round rail handguard is comfortable to grip, even for extended periods.

The upper is relatively lightweight, making it easy to handle and maneuver. There is no significant learning curve associated with using this upper.

Durability & Maintenance

The materials used in the Jacob Grey Firearms 5.56 NATO Complete Upper Assembly suggest that it should last for thousands of rounds with proper care. The hard coat anodized finish is resistant to scratches and corrosion.

Maintenance is simple, requiring only regular cleaning and lubrication of the BCG. The barrel is not chrome-lined, so it may require more frequent cleaning to prevent corrosion.

Accessories and Customization Options

The Jacob Grey Firearms 5.56 NATO Complete Upper Assembly is compatible with a wide range of AR-15 accessories. The M-LOK handguard allows for easy attachment of lights, lasers, and foregrips. The standard 1/2×28 barrel threads allow for the use of various muzzle devices, such as suppressors or compensators.

The upper is compatible with most AR-15 lower receivers and magazines. Aftermarket charging handles and bolt carrier groups can also be used, but the included components are of high quality and should not need immediate replacement.

Pros and Cons of Jacob Grey Firearms 5.56 NATO Complete Upper Assembly

Who Should Buy Jacob Grey Firearms 5.56 NATO Complete Upper Assembly?

The Jacob Grey Firearms 5.56 NATO Complete Upper Assembly is perfect for individuals seeking a compact and reliable AR pistol for home defense, truck gun use, or recreational shooting. It is also a good option for those looking to build a budget-friendly AR pistol without sacrificing quality.

Those who prioritize extreme accuracy or plan to shoot primarily at long ranges may want to consider a longer barrel. Individuals who are sensitive to recoil or noise may find the short barrel unpleasant to shoot. A linear compensator or suppressor would be a must-have.

Conclusion on Jacob Grey Firearms 5.56 NATO Complete Upper Assembly

The Jacob Grey Firearms 5.56 NATO Complete Upper Assembly is a well-built and reliable upper that offers excellent value for the price. Its compact size and dependable performance make it a great option for a variety of applications.

The price of $454.50 is justified by the quality of the components and the overall performance of the upper. I would personally recommend this upper to anyone looking to build a short-barreled AR pistol.

If you’re in the market for a compact and reliable AR pistol upper, the Jacob Grey Firearms 5.56 NATO Complete Upper Assembly is definitely worth considering. Give it a shot – you won’t be disappointed!