“Are you ready to feel the BuRN?” The BRN-180 is the new hotness in black rifles. Based upon the original AR-180 design from Gene Stoner and the Armalite crew, the BRN-180 series from Brownells is setting the black rifle world on fire.

We’ve just recently completed our build, and now we finally have our official SOTG review of the BRN-180 out to the public.

The Brownells BRN-180S; a faithful tribute to the AR-180.

History of the AR-18 and AR-180

Gene Stoner, like Mikhail Kalashnikov, turned the military rifle world on its collective head. Stoner and his engineering crew at Armalite not only designed the AR-10, which led to the AR-15 and the M16, they also kept going and created the AR-18.

A quick Internet search will reveal that the AR-18 was a select-fire rifle designed for military application. The AR-180 was a semi-automatic version of the rifle made for universal sales to citizens.

Some would argue that the AR-180 design actually took all of the benefits of the AR-15; aircraft grade aluminum and polymer, lightweight and good ergonomics, and improved upon them with a better operating system. To this day, some people have a violent hatred for the direct gas-impingement operating system.

Sadly, the AR-15/M16 overshadowed the AR-18/180 and the gun never really caught on in the early days of the black rifle. However, several companies did indeed borrow many of the ideas from the AR-180. Take a look at the SIG MCX operating system and you will see striking similarities.

Brownells BRN-180

A few years ago, Brownells, Inc. announced the launch of their Retro Rifles program. The engineers at Brownells took the original specifications for the classic Armalite rifles and produced them as factory new guns. Brownells has two versions of the AR-10, and several incarnations of the AR-15 as it progressed toward the eventually adopted M16A1.

The next natural step was the AR-18/180. What the guys at Brownells have done is resurrect the classic rifle design as factory new parts under the BRN-180 category. Brownells offers two BRN-180 lower receivers; a modern version that resembles the AR-15 called the BRN-180M and a more classic looking version called the BRN-180.

The lower receivers use AR-15 triggers and lower parts kits. These are premium built 7075 T-6 aluminum receivers. One of the nice features is a threaded bolt catch pin that eliminates the need to pound in a roll pin. The lowers have a trigger guard built into the body of the receiver.

Another distinctive feature is the use of an M1913 Picatinny rail mounts at the rear of the lower receiver where you would normally expect to see the buffer tube. The entire bolt carrier and recoil mechanism can be found in the upper receiver of the BRN-180. This feature eliminates the need for an AR style buffer tube. What the design does is allow for a wide variety of stocks and stabilizing braces to function here.

A lightweight, compact Rifle Caliber Pistol, the BRN-180S

Our BRN-180 Build.

For this review, we built a BRN-180 rifle caliber pistol (RCP). The base for the project was the BRN-180M lower receiver. Onto that we would add the BRN-180S complete upper receiver group. The 180S uses a shorter barrel than a standard rifle; 10.5 inches. Brownells offers rifle length 180 uppers with 16 and 18.5 inch barrels.

All the chambers for the BRN-180 uppers are cut for the .223 Wylde cartridge. As you may know, .223 Wylde allows the end user to safely fire .223 Remington or 5.56mm NATO. The .223 Wylde chambering seems to be the best of both worlds for modern black rifle users.

Surrounding the barrel of the upper is an aluminum handguard with M-Lok attachment points left, right, and below. An M1913 Pic rail runs the entire length of the upper receiver. The barrel rifling is a 1-8 twist with 1/2×28 TPI threads at the muzzle. A replica 3-prong AR-180 flash suppressor is on the business end of the gun.

The AR stripped lower parts kit I used came from the Brownells site. For the trigger group, I chose to install a HiperFire trigger. This trigger group is a bit more complex than your standard semi-automatic AR trigger. However, I have found that if you follow the manufacturer’s instructions that it is not all that difficult to put a HiperFire trigger in your AR.

The new FS1913 side-folding brace from SB Tactical uses an aluminum strut.

Brace Yourself!

I will assume the majority of the reading audience understands the difference between a Short-Barreled Rifle (SBR) and a Rifle Caliber Pistol (RCP). The firearm that I assembled is a RCP. That being the case, I was able to choose from one of several types of stabilizing braces available.

Chosen for this project was the model FS1913 from SB Tactical. This is the latest upgrade to the FS1913 design with an aluminum strut versus the polymer of the original. The FS1913 mounts directly to any 1913 Picatinny rail. The brace has a side folding mechanism and it folds to the left on the BRN-180, so as to be away from the action and ejection port. Yes, the BRN-180 will fire safely with the brace folded.

One sweet little feature on the BRN-180S upper receiver is the installation of a small round, rubber bumper. When folded, the brace sits right against the rubber bumper. On the original AR-180 rifle, the full-sized stock folded to the left side and mated with a nipple like device on the lower receiver.

Our Optic Choice for the BRN-180.

The last couple pieces of the puzzle would be the installation of red dot optic and backup sights. For the optic I went to the Primary Arms website and ordered their new ACSS Cyclops optic with a co-witness mount.

The ACSS Cyclops has a red illuminated BDC (bullet-drop compensator) reticle with basic range estimation for the 5.56mm cartridge. The reticle does not have to be in the on position to function, but the red light does help you to pick it up rapidly for close in shots. As for backup iron sights, I found a set of Yankee Hill Manufacturing sights in a bin of AR parts.

Before leaving for the range, I disassembled the bolt carrier group and applied a coating of EDC CLP. This red colored gun lube was recommended to me by a good friend whose opinion I trust. The factor that is supposed to make EDC different from other lubricants is positively charged molecules. In other words “it’s science”.

Note the M-Lok rail and the ACSS Cyclops optic from Primary Arms.

Range Time with the BRN-180.

I have been gathering the parts for this project for about six weeks. When I finally had them all together I could not wait to get out and shoot. At 1 p.m. on Sunday I had the RCP assembled. At 3 p.m. that same day was in the BLM land on the salt flats of the Great Salt Lake in Utah.

We had to know if the gun would run. So we gave the sights a rough zero, and got to work. I had grabbed four AR mags filled with Black Hills .223 Remington ammo. Also, I knew if something went wrong it would not be the ammo, but my skill as a gun builder.

I did not expect to encounter any problems, and I the firearm did not disappoint. The gun ran fantastically well. Completely assembled with optic and brace the new BRN-180S weighed 7 pounds 1 ounce. Recoil was modest as you would expect. To stay on target for rapid firing you need only to lean into the gun.

Yes, the plan is obviously to shoot the BRN-180S a great deal more and stretch it out to see what kind of accuracy we can get. However, for we are now glad to know that the gun’s construction went smooth, and it works well.

Let me know what you think of this build in the comment section below. Click Here to Leave a Comment

More to come in the future. Stay tuned!

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Professor Paul Markel

Founder & CEO at Student of the Gun

Paul G. Markel has worn many hats during his lifetime. He has been a U.S. Marine, Police Officer, Professional Bodyguard, and Small Arms and Tactics Instructor. Mr. Markel has been writing professionally for law enforcement and firearms periodicals for nearly twenty years with hundreds and hundreds of articles in print. Paul is a regular guest on nationally syndicated radio talk shows and subject matter expert in firearms training and use of force. Mr. Markel has been teaching safe and effective firearms handling to students young and old for decades and has worked actively with the 4-H Shooting Sports program. Paul holds numerous instructor certifications in multiple disciplines and a Bachelor’s degree in conflict resolution; nonetheless, he is and will remain a dedicated Student of the Gun.

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