Brownells BRN-180 Upper
Brownells has released a BRN-180 lower to match its side-charging upper receiver. T. Logan Metesh

Last year, Brownells announced the addition of the BRN-180 side-charging upper receiver, and now they have a lower receiver to match.

The design of the BRN-180 was inspired by the Armalite AR-180 from the 1960s. The AR-18 was developed as a successor to the original AR-15/M16 design and the AR-180 was a semi-auto civilian version of the AR-18.

Brownells BRN-180 Upper
TK T. Logan Metesh

The BRN-180 incorporated many of the AR-18/AR-180 improvements, including its robust and reliable gas piston operating system. One of the biggest differences between the AR-18/AR-180 design and the AR-15 is that the former has recoil springs housed in the receiver instead of the AR-15′s more complicated buffer mechanism in the buffer tube and buttstock. This allows for the use of side-folding stocks, something the AR-15 platform cannot accommodate.

Like the original, the BRN-180 bolt carrier rides smoothly on a pair of guide rods. The carrier is buffered at the rear by a built-in polymer buffer with a molded-in steel plate that captures the guide rods. The bolt replicates the original AR-180 bolt design, right down to its use of a standard AR-15 extractor.

Brownells BRN-180M
The new Brownells BRN-180M lower paired with a BRN-180S upper that was on hand to shoot at this year’s Industry Day at the Range. Joseph Albanese

Most importantly, Brownells designed the upper to be compatible with any standard, mil-spec AR-15 lower receiver. However, there’s always room for improvement when it comes to design and performance, so that’s why Brownells has now released lower receivers designed to work specifically with their BRN-180 uppers.

The BRN-180 lower receivers do away with the traditional receiver extension threads, and in their place have a milled-in Picatinny rail section for mounting of stocks or braces.

Brownells BRN-180 Upper
The left side of the new Brownells BRN-180 lower receiver. T. Logan Metesh

The receivers are made from billet 7075 T-6 aluminum with a hard-anodized finish, have an integral oversized trigger guard, and the unique features of a threaded bolt catch pin and captive set screw for the takedown pin detent spring.

They’re offering two varieties: the BRN-180 lower has the design and appearance of the original AR-180 lower receivers, while the BRN-180M looks like a more traditional AR-15 receiver.

The BRN-180 stripped lower has an MSRP of $129, and the BRN-180M stripped lower has an MSRP of $149.

Brownells BRN-180 Upper
A display of complete Brownells BRN-180 and BRN-180S rifles on display at SHOT Show 2020. T. Logan Metesh