Out of stock
SKU: 78000723
UPC: 050806113664
The Brownells BRN-180 Gen 2 16" 7.62x39mm Upper Receiver Assembly brings the short-stroke gas piston design of Eugene Stoner's AR-18/AR-180 platform to shooters who want a cleaner-running alternative to direct impingement systems. Built for compatibility with mil-spec AR-15 lower receivers, this upper allows folding stock operation—something standard AR-15 configurations cannot achieve due to buffer tube requirements. For shooters building a compact rifle chambered in the proven 7.62x39mm cartridge, this assembly delivers reliability without requiring a complete platform change.
The 16-inch barrel is constructed from 4150 carbon steel with a nitride finish and button-rifled bore featuring a 1:8 twist rate optimized for the 7.62x39mm cartridge. The short-stroke gas piston operating system includes two adjustable gas settings, allowing tuning for suppressed or unsuppressed use. A machined 7075 T6 aluminum receiver with hardcoat anodized finish houses the multi-lug rotating bolt with black oxide coating. The self-contained recoil system uses dual guide rods housed entirely within the upper receiver, eliminating the need for a buffer tube. Handguard attachment uses a single locking screw for secure mounting, and the full-length Picatinny rail accommodates optics and accessories. The muzzle features 5/8-24 TPI threads fitted with a three-prong AR-180 replica flash suppressor.
This upper pairs effectively with 7.62x39mm AR-15 magazines—C-Products Duramag and Unimag are recommended for reliable feeding. The folding capability makes it well-suited for truck guns, backpack configurations, or any application where compact storage matters. Chambered in 7.62x39mm, shooters gain access to widely available, affordable ammunition while maintaining intermediate-range effectiveness. Browse our magazines selection for compatible feeding options and our firearms inventory for complete builds.
No. The BRN-180 Gen 2 uses a self-contained recoil system with dual guide rods housed entirely within the upper receiver. This eliminates the buffer tube requirement and allows the use of folding stocks, side-folding braces, or fixed stocks without a buffer assembly.
The upper is designed for AR-15 pattern 7.62x39mm magazines. C-Products Duramag and Unimag magazines are specifically recommended by the manufacturer for reliable feeding and function with this upper receiver assembly.
Yes. The short-stroke gas piston system features two adjustable settings, allowing you to tune gas flow for standard unsuppressed shooting or reduce it when running a suppressor to manage back pressure and cycling speed.
The upper is designed for compatibility with mil-spec AR-15 lower receivers. It attaches using standard takedown pins and requires no modifications to a standard lower, though you will not need the buffer tube, buffer, or recoil spring.
The 16-inch barrel features a 1:8 twist rate, which is optimized for stabilizing the range of bullet weights commonly available in 7.62x39mm ammunition, from lighter 123-grain loads to heavier subsonic projectiles.
WARNING ⚠️ You must be 18 or older to purchase shotgun or rifle ammunition and 21 or older to purchase handgun ammunition and firearms. Please reference our requirements for ammunition orders to "restricted" states HERE. Always make sure you use the correct ammunition for your firearms. Ammo cannot be shipped to a PO Box. Please reference state & local laws before making a firearm or ammunition purchase.
