Rather than developing something new, Brownells has tackled the AR folding stock problem by revisiting an existing, if somewhat forgotten, design and giving it a modern twist with the new BRN-180 upper assembly.
Based on the original 1960s era AR-180, this upper employs a robust short-stroke piston system, a three prong flash hider, a reciprocating side charging handle and a twin internal guide rod system replacing the typical AR buffer assembly. This upper has been configured to drop onto any mil-spec AR-15 lower assembly with desirable modern updates including a .223 Wylde chamber, 1:8 twist rifling, and an easy to remove M-Lok handguard.
Manufactured with completely new materials and thoroughly-modern methods, this upper has a suggested retail price of $799, making it one of the most affordably priced piston driven options currently on the market. Look for the BRN-180 upper listed under product number #078-000-483 on the Brownells website.