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BRN-4® UPPER RECEIVER ASSEMBLIES Reviews & Ratings

BRN-4® UPPER RECEIVER ASSEMBLIES

Assembled from All New Components – Fits Standard AR-15 Lowers

The BRN-4® Upper Receiver is now available as an Assembled Upper, with Barrel and Gas System installed. Simply add your preferred HK® 416 compatible handguard and any 1/2-28 muzzle device, and you’re ready to hit the range!

Built from the ground up, the core of the BRN-4® Upper Receiver is an all new Bolt Carrier Group, featuring a phosphate carrier and a chrome bolt. The carrier itself is machined from one piece of forged 8620 steel. The bolt is precision machined from 9310 tool steel and headspaced prior to and after barrel installation.

The new BRN-4® barrel, produced by Faxon®, is available in a variety of profiles and lengths to suit your needs. Barrels are chambered 5.56x45mm NATO, are button rifled with a 1-7 twist, 1/2-28 muzzle and come with the appropriate gas block for a given barrel length. Barrels are available in a medium or heavy profile. The heavy profile ensures a rigid and robust platform for precision shooting. The medium profile balances the desire to have a lighter piston configuration, while still having plenty of barrel material to prevent drifting of grouping as the barrel heats.

The upper receiver utilized in this assembly is made completely new, from billet, to mirror the profiles commonly found on forged upper receivers. Contours of the upper are entirely machined from billet, so rounded areas such as the cam pin protrusion and complex contours will show machine passes more prominently. The machined upper is finished with matte black hard coat anodizing. The proper piston bushing is installed to eliminate any piston wear on the aluminum part, and is secured in place with blue threadlocker. The BRN-4® features much longer barrel nut threads, engaging the barrel extension over a much larger surface area than a standard AR-15. This ensure that the barrel is rigidly mounted with the pre-installed barrel nut. Barrel nut is torqued properly with AeroShell Grease 64 applied to the upper receiver threads. The barrel nut is reinstalled 3 times to ensure an accurate torque spec is achieved.

Gas blocks are vented forward, to reduce gas sent rearward into the system, and are mated specific to the 10.4 or 14.5/16 inch barrel lengths.

Upper includes Magpul ejection port cover and mil-spec charging handle.

Handguard installation is extremely simple, just slide handguard over the barrel and tighten one bolt. Be sure to follow any specific instructions advised by the manufacturer.

Muzzle devices installation is also straightforward, as the barrel is 1/2-28 and the BRN-4 upper is compatible with common upper receiver “rods” and jigs. Any AR-15 1/2-28 muzzle device will be compatible.

Brownells recommend H1 or H2 recoil buffer with carbine recoil spring for optimal operation.

*** Brownells recommends use of 5.56x45mm NATO newly manufactured quality ammunition for optimal operation

All BRN-4 Upper Receiver Assemblies are test fired before final packaging. Upper may display signs of firing, such as brass marks on the shell deflector or slight fouling inside.

ALL NFA RULES APPLY.

See all of our AR15s and AR15 parts here.

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Reviews Summary

The BRN-4® Upper Receiver Assemblies receive mixed reviews, praised for functionality and value, especially for 416 builds. However, many users criticize the rough machining and external finish, expressing frustration at malfunctions and quality control. While some enjoy the performance, especially when shooting suppressed, others report serious issues that overshadow satisfaction.

What Reviewers Are Saying

Quality of Machining

68%

A significant number of reviewers express disappointment regarding the machining quality of the BRN-4 upper. Many noted rough chatter marks and inadequate finishing for a product within its price range. This has led to dissatisfaction, with some reviewers feeling that the finish quality is embarrassing compared to competitors.

Functionality and Performance

55%

Despite concerns about machining quality, numerous reviewers appreciated the performance of the BRN-4 upper. Many reported successful builds and smooth shooting experiences, especially when using quality ammunition. The reliability of the product earned it praise from users, indicating satisfaction with its functionality.

Value for Money

45%

Several reviewers highlight the affordability of the BRN-4 upper compared to authentic HK models. Users feel it provides decent value for those looking to build an HK416 clone. The competitive pricing draws interest, although some believe that the quality does not meet expectations relative to its cost.

Customer Experience and Support

30%

While the product received mixed ratings, some reviewers shared positive experiences regarding their purchases, including quick shipping and satisfactory customer support. Nonetheless, issues with product malfunctions point to potential gaps in quality assurance, suggesting room for improvement in the overall customer experience.

Accessory and Component Issues

25%

A few reviews pointed out that certain essential components, like charging handles and ejection port covers, do not meet user expectations. Reviewers were disappointed by durability concerns, such as parts breaking during assembly, indicating that improvements in included accessories could enhance overall satisfaction.

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Expensive should have included more

I’m really disappointed I believe that a hand guard and or a bolt carrier group should have been included at that price

by STEPHEN D. on October 24, 2024

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Was this review helpful? 3

Overgassed in 10.4in when shot suppressed

Got my SBR approval (in 3 days, go figure!) from the ATF so I grabbed my rifle, my Gemtech G5T, and some 20rd PMAG's loaded with M193's and headed to the sandpit. The rifle, built on a complete JP-15 receiver and SCS buffer, Ergo grip, Midwest Industries 9in MLOK hand guard, and Magpul PRS-Lite buttstock and AFG is predictably front heavy, but otherwise handles well and shoulders naturally. The ergonomics come together and the weapon feels instinctive. Other equipment: Troy Industries HK profile tritium BUIS, Leupold Deltapoint Pro w/ offset mount, GG&G Giles sling with Magpul QDs, CMMG ambidextrous magazine release, Warhammer charging handle, Gemtech Vortex flash hider w/ QD lugs, and aforementioned Gemtech G5T can. On firing the first round, however, a lot of gas came out of the ejection port. A lot. My old SR556 dumped less gas, but it had an adjustable gas block. My advice is don't get the 10.4in configuration unless you've budgeted a 416N gas block (and good luck finding one), and the machinist time to open up the gas port. I like the finish, it's easy to clean. As has elsewhere been pointed out, the machining/tooling could be better... it's not HK-quality, but then it's not HK-pricing either so you get what you pay for. I don't understand why Brownell's doesn't (1) ship the barrels ported to 1.6mm, and (2) offer an off-the-shelf configuration with a 416N or A5 gas block, because the kit isn't usable as-is suppressed.

Would you recommend this? Yes, I would recommend to a friend

Needs refining

POS plastic magpul ejection door broke on the second opening. Has a donut for an ejection assist. Not a big fan of donuts. Charging handle is worthless if you’re using a scope unless you don’t like your knuckles. Headspace checked ok. Don’t have the special tool to check the barrel torque. That’s needs to be done before theres even a thought of firing it. So another 100 to 200 for a brake or flash suppressor, 100 for a functional charging handle, 300 to 500 or more for a handguard. I understand about the extra expenses for the flash suppressor and handguard.

by Jenn on March 06, 2024

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Was this review helpful? 8

Works, rough finish

Bought a 10.4 medium contour, it functions fine but the machining is rough at best. The finish pass could have been done much better to smooth the ball mill toolmarks. The index slot for the handguard tab was also too wide, I used the included spacer and still needed to add 0.003" shim stock to each side to get it to fit tight. If you plan to use it for fun and slap krylon on it, it'll be fine. Otherwise, buy the other components and source another stripped upper.

by Eric J. on November 16, 2023

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Was this review helpful? 27