Brownells Releases BRN-180S Uppers in .300 BLK

This upper receiver comes with a 10-inch barrel and is a modern interpretation of the AR-18/AR-180 rifle.

A man in sunglasses and a cap aims a rifle at a shooting range.
Brownells’ new BRN-180S upper receiver in .300 BLK will fit any current mil-spec AR-15 lower receiver.Brownells

Brownells recently introduced its new BRN-180S Gen2 complete upper receiver, chambered in .300 BLK with a 10-inch barrel and an adjustable gas system that can handle the fastest or slowest, suppressor-friendly ammo out there. The upper, with a 7075 T6 aluminum receiver and handguard, fits any current mil-spec AR-15 lower for a compact AR pistol or SBR build.

Brownells' BRN-180 platform is based on the AR-18/AR-180 rifles made in the 1960s, which were follow-up designs to the AR-15. It includes a robust, reliable gas-piston operating system. The new BRN-180S introduces key features to improve reliability and usability in a shorter configuration.

The .300 BLK requires a shorter system to ensure reliability with a wide variety of ammunition. The resulting gas system has a two-position setting so users can find the most reliable configuration for their ammunition and suppressor. The handguard is now retained with a single large locking screw that provides a more consistent handguard lockup. Additionally, the handguard can be removed without having to take out the internal components of the upper receiver.

As with the original design, the BRN-180S bolt carrier rides on a pair of guide rods. The barrel is machined from 4150 carbon steel with a hard nitride finish. The .300 BLK BRN-180S also features a 1:8 twist, which complements a wide variety of ammunition. The upper comes with a replica of the original AR-180′s unique three-prong flash hider, but the barrel features standard 5/8-24 muzzle threads, so users can add any muzzle device or suppressor they desire. SRP: $899.