The most interesting member of this family doesn’t even carry Brownells Retro Rifle branding, as it’s a modern rendition of the lesser known AR-18/AR-180. The BRN-180 is a modern design with a full-length rail extending from the receiver to the end of the 15-inch M-Lok hand guard. It’s immediately obvious that this isn’t an ordinary complete AR upper
receiver, because a reciprocating charging handle protrudes from the dust-port area on the right side of the receiver.
The BRN-180 has dual internal rod-guide buffer springs riding above the bolt carrier, completely eliminating the need for a rear buffer tube. This makes it possible to do things that are normally impossible with a conventional AR, such as mounting a collapsible wire paratrooper-type stock, or shooting it with a buffer-mounted stock folded to the side.
The other area where the BRN-180 deviates from AR orthodoxy, while still remaining historically accurate, is the use of a gas piston operating system in place of the now-common direct impingement system. The AR-18 rifle built for the military, but never accepted into common use, was equipped with a similar gas-piston system that was the cause of much controversy at the time of its introduction.
The BRN-180 complete upper is chambered in .223 Wylde, enabling it to safely fire both .223 Rem. and higher-pressure 5.56 NATO ammo. The BRN-180 complete upper with 16-inch barrel is currently available for pre-order for $799, and Brownells is considering development of a short-barreled version of the BRN-180, depending on interest levels.