Brownells Introduces BRN-180 Gen2 Uppers and Adds a .300 Blackout Version

    Brownells BRN-180 Gen2 and 300 Blackout (1)

    Brownells has released the second generation of their BRN-180 upper receiver assemblies and also added a .300 Blackout version of the shorter barreled BRN-180S upper. The BRN-180 family of products is based on the AR-18/AR-180 design and is made in cooperation with PWS and FM Products. Let’s see what new features BRN-180 Gen2 uppers have compared to the first generation ones.

    Brownells BRN-180 Gen2 and 300 Blackout (2)

    All BRN-180 Gen2 uppers feature a two-position adjustable gas block.

    There are two changes/improvements incorporated into the design of second generation BRN-180 upper receivers. One of them is the addition of a large single handguard disassembly screw located at the bottom rear portion of the handguard. This is a much more robust handguard attachment mechanism which also makes the handguard disassembly a much quicker process providing easier access to the gas piston assembly. The second difference from Gen1 is that all Gen2 uppers have adjustable gas blocks. In the first generation, only the shorter-barreled BRN-180S uppers had adjustable gas systems.

    Brownells BRN-180 Gen2 and 300 Blackout (3)

    The updated handguard attachment mechanism has a single disassembly screw.

    The BRN-180 Gen2 family of upper receivers currently consists of the four models shown in the picture below. The 5.56/223 uppers have Wylde chambers and come with 1/2×28 muzzle threads. The .300 Blackout version has a 5/8×24 muzzle thread pitch. Note that both BRN-180S uppers have the same handguard length, however, due to the shorter gas system, the handguard of the .300 Blackout upper has a top cutout to provide access to the gas block. The barrels of all four uppers have a 1:8″ twist rate and come equipped with three-prong flash hiders. Depending on the caliber and size, the weight of BRN-180 Gen2 upper receivers varies from 3lb 15oz to 4lb 13oz.

    Brownells BRN-180 Gen2 and 300 Blackout (1)

    Four models of BRN-180 Gen2 line of upper receiver assemblies.

    Brownells BRN-180 Gen2 upper receivers and handguards are machined out of 7075 T6 aluminum and have a black hard coat anodized finish. The barrels are made of 4150 carbon steel with a nitrided finish/surface treatment. Being inspired by the AR-18/AR-180, the BRN-180 upper receiver assemblies feature a similar short-stroke gas piston system and dual-spring recoil spring mechanism that does not extend past the upper receiver thus allowing to have a folding stock and shoot the firearm with the stock folded. These upper receivers are compatible with mil-spec AR-15 lower receivers.

    Brownells BRN-180 Gen2 and 300 Blackout (5)

    All four models of BRN-180 Gen2 upper receiver assemblies are listed on the company’s website at an identical price of $899.99.

    Lastly, below you can find a couple of videos published by Brownells showing the features and disassembly procedure of Gen2 BRN-180 uppers.

    Images by Brownells Inc.,

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    Being a lifelong firearms enthusiast, Hrachya always enjoys studying the history and design of guns and ammunition. He also writes for and
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