Brownells Brn-180S Gen 2 Upper Receiver 223 Wylde 10.5'' Barrel Black

The Brownells BRN-180S Gen 2 upper receiver in .223 Wylde with a 10.5" barrel brings modern engineering to a platform inspired by the classic AR-180. Built in collaboration with PWS and FM Products, this short-stroke piston upper is engineered for reliability and real-world usability, making it a solid choice for shooters who want something different from the standard direct-impingement AR-15. The compact configuration and adjustable gas system give you flexibility to dial in reliable function across different ammunition loads and suppressor setups.

The BRN-180S Gen 2 improves on the original with an adjustable two-position gas system now standard across the line. This lets you tune the piston action to your ammo and conditions without swapping parts—just flip the selector to find the sweet spot. The redesigned handguard attachment uses a single large locking screw for rock-solid consistency, and you can strip the handguard without disassembling internal components to access the gas adjustment. The free-float M-LOK handguard is scaled to the short barrel, terminating just forward of the gas block with a cutout for easy access to the gas lever.

Construction is solid throughout. The receiver and handguard are machined from 7075 T6 aluminum and hardcoat anodized for durability. The 10.5" 4150 carbon steel barrel is finished in hard Nitride, resists wear, and rifled 1-in-8" to handle both .223 Remington and 5.56mm NATO. The bolt is Nitride-finished and follows the original AR-180 design, including a standard AR-15 extractor. Dual guide rods support the bolt carrier, which is buffered at the rear by a built-in polymer buffer with a steel plate. Threading is standard ½"-28 for the .223 Wylde, so you can add any modern AR muzzle device. The signature three-prong flash hider is included—that distinctive hemispherical bottom prong does real work suppressing dust signature when you're prone. Compatible with mil-spec AR-15 lowers, and the whole package weighs 4 lbs.

Key Features

• Short-stroke piston operation with proven AR-180 design principles
• Adjustable two-position gas system for tuning to your ammo and suppressor
• Single-screw handguard lockup for consistent zero and rigidity under heat
• Free-float M-LOK handguard with accessible gas adjustment cutout
• 7075 T6 aluminum receiver and handguard, hardcoat anodized finish
• 4150 carbon steel barrel with hard Nitride finish, 1-in-8" twist
• Nitride bolt with standard AR-15 extractor
• Dual guide rod system with molded polymer buffer
• Replica three-prong flash hider with dust-signature reduction
• MillSpec AR-15 lower compatible

Specifications

Frequently Asked Questions

Will the BRN-180S Gen 2 work with my mil-spec AR-15 lower?

Yes. The BRN-180S Gen 2 upper is designed to be compatible with standard mil-spec AR-15 lowers, making it straightforward to drop onto an existing lower or build a complete rifle.

What's included in the box?

The upper receiver assembly ships complete with the 10.5" barrel, adjustable gas piston system, free-float M-LOK handguard, Nitride bolt, and the replica three-prong AR-180 flash hider.

Can I use .223 Remington and 5.56mm NATO in the same upper?

Yes. The .223 Wylde chamber is designed to safely and accurately fire both .223 Remington and 5.56mm NATO ammunition, giving you flexibility in ammo selection.

How do I adjust the gas system?

The adjustable gas system has two selectable positions accessible via a lever on the side of the gas piston. The handguard includes a cutout for easy access to the adjustment without disassembling other components. You can tune between the two settings to optimize function with your specific ammunition and suppressor setup.