Out of stock
SKU: 78000724
UPC: 050806113671
The Brownells BRN-180S Gen 2 is a complete 7.62x39mm upper receiver assembly built around a short-stroke gas piston operating system, sized for compact builds with a 10.5-inch barrel and a 24.5-inch overall length. It drops onto any standard mil-spec lower, which makes it a straightforward path to a piston-driven 7.62x39 rifle without reworking your existing setup. Shooters building a maneuverable carbine or stocking parts for an AR-platform project will find this upper handles the stout 7.62x39 cartridge in a package that stays short and balanced up front.
The design draws on Eugene Stoner's later AR-18/AR-180 work, co-developed with PWS and FM Products. The receiver and M-LOK handguard are machined from 7075 T6 aluminum with a matte black hardcoat anodized finish, while the 10.5-inch barrel is 4150 carbon steel with a nitride coating and a 1-9.5 twist tuned for the 7.62x39mm round. A two-position adjustable gas block lets you tune the system for suppressed or unsuppressed use. The barrel wears a 5/8-24 threaded muzzle with a three-prong AR-180 style flash hider. A twin recoil guide rod system contains the springs inside the upper, so no buffer tube, recoil spring, or receiver extension is needed, which is what allows a folding stock. The reciprocating side-charging handle doubles as a brass deflector.
This upper suits anyone who wants a folding, piston-driven 7.62x39 carbine for truck guns, home defense, or range work where compact length matters more than long-range reach. Because the recoil system is self-contained, you can run it on a folding-stock or pistol-brace lower for storage and transport that a traditional buffer tube won't allow. Pair it with a complete mil-spec lower or stock up from our AR upper selection, and browse our lower receiver options to finish the build. For full rifles ready to run, see our carbines.
No. The twin recoil guide rod system is self-contained inside the upper, so it does not require a standard buffer tube, recoil spring, or receiver extension. This is what makes the assembly folding-stock capable when paired with a compatible lower.
Yes. It is a complete plug-and-play upper that drops onto any standard mil-spec AR-15 lower. Because the recoil system lives inside the upper, you are not limited to lowers built around a traditional buffer assembly.
The 7.62x39mm variant uses a 1-9.5 inch twist, which is matched to the cartridge per the manufacturer's published specifications. The barrel is 10.5 inches of 4150 carbon steel with a nitride finish.
The muzzle is threaded 5/8-24 TPI and ships with a three-prong AR-180 style flash hider that can be swapped for a suppressor mount. The two-position adjustable gas block lets you tune gas flow for suppressed or unsuppressed shooting.
With the 10.5-inch barrel, the upper measures 24.5 inches overall and weighs roughly 4.65 lbs depending on configuration, making it well suited to a short, maneuverable carbine build.
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