August 01, 2022
By David Fortier
Brownells, which is best known for distributing parts, gunsmithing tools and accessories, has recognized the popularity of retro rifles and responded with an entire line of Vietnam-era reproductions. One of its unique offerings is the BRN-180 upper receiver, which is interestingly enough not AR-10 or AR-15 but rather is patterned after Armalite’s own competitor to the AR-15: the AR-18.
The AR-18 was designed by Armalite’s dream team of Arthur Miller, Eugene Stoner, George Sullivan and Charles Dorchester in 1963. It was designed to be an economical alternative to their previous AR-15 design, and it was intended for foreign military sales. A semiauto version of the selective-fire AR-18 was also developed and marketed as the AR-180. Unlike their AR-15, though, the AR-18/AR-180 was not a success on either the foreign military or domestic commercial market.
Even so, the AR-18 and AR-180 were blessed with some great features. They were relatively inexpensive to manufacture using traditional methods, and they featured a simple short-stroke gas-operated system that proved reliable. Dual-recoil springs were contained inside the receiver, which allowed for a side-folding stock, plus the design was light, handy and easy to use. The bolt carrier assembly is simple to strip, and the basic operating system has been resurrected time and time again by other manufacturers.
Rather than trying to build a clone rifle or reproduction of the original AR-18/AR-180 Brownells decided to do something a bit different. It decided to build an upper receiver as it felt it would currently appear, and it is designed to fit onto a standard AR-15 lower receiver.
The receiver is machined from 7075 T6 aluminum—in contrast to the original’s stamped sheet-metal and spot-welding construction. The result is much better looking and much easier to manufacture than the original. The flattop upper receiver has a 1913 rail for mounting iron sights and/or optics.
The 16-inch barrel is machined from 4150 carbon steel and is cut with a .223 Wylde chamber and 1:8 rifling. In place of the original’s chrome-plated bore is a hard nitride finish. Barrel profile is fairly light, which helps to keep the weight down, and the barrel is tipped with a replica of the AR-180’s three-prong flash suppressor—complete with its hemispherical bottom prong. Surrounding the barrel is a free-floating aluminum handguard with a 1913 rail at 12 o’clock and M-Lok slots at three, six and nine o’clock.
Riding inside the upper receiver is the classic AR-18/AR-180 style bolt carrier assembly. This features a multi-lug rotating bolt, and as I mentioned, the assembly rides on dual guide rods.
These horizontal guide rods feature the recoil springs, which unlike an AR-15 are contained within the confines of the upper receiver. Due to this, there is no need for a receiver extension or buffer like on an AR-15—so you can not only outfit your BRN-180 with a side-folding stock but you can shoot it with the stock folded, 1970-’80s action-movie style.
For this review I dug-out my favorite San Tan Tactical lower receiver, which happens to be fitted with a Law Tactical folding hinge assembly. The BRN-180 proved a slightly tight fit on this but not tight enough to be an issue. Next I added a set of Midwest Industries new combat rifle sights and a Burris AR-332 3X scope.
One thing to keep in mind when selecting optics for use on the BRN-180 is the dogleg charging handle. It angles up close to the 1913 rail on top of the receiver, and due to its placement, optics and mounts with locking hardware on the right side may prevent operation of the reciprocating charging handle. Just something to keep in mind.
The BRN-180 feels decently balanced and just a trifle light toward the muzzle. The handguard is comfortable, and the light barrel profile makes the piece swing quickly from target to target.
While the right-side-mounted reciprocating dog-leg bolt handle is a throwback, on the plus side you can put your boot to it to jack the bolt open if needed. The downside is it’s hard to reach, especially with an optic mounted—unless you are left-handed.
Recoil is fairly mild, and the muzzle stays flat, facilitating fast follow-up shots. The recoil impulse with 55-grain ammunition doesn’t feel much different from a standard AR-15. Ejection was to four o’clock, with the fired cases going approximately four feet.
Because the BRN-180 fits onto an AR-15 lower, you can use standard AR-15 magazines rather than having to hunt for original AR-180 mags, and the bolt locks back on the last shot.
Accuracy both from the bench and from position proved quite good. Better still, the BRN-180 proved fun on the range. I ran it through drills inside 50 yards, shot it offhand on steel at 100 yards, and kneeling, sitting, prone and off barricades and a tank trap out to 500 yards.
The BRN-180 strips easily for cleaning. Pop the pivot pin, tip the upper and draw the dual recoil springs and their guides straight out of the back of the receiver. Pull the bolt to the rear, withdraw the charging handle and the bolt can be dropped out. The bolt strips easily without tools.
With the bolt guides removed you can remove the U-clip that retains the handguard. Removing this gives access to the gas system. Again, this is easily taken down. Because this is a piston-operated system, the receiver and bolt carrier assembly remains quite clean compared to a direct-impingement AR-15. Also, the BRN-180 comes with two piston cups allowing use both suppressed and unsuppressed.
Brownells BRN-180 is an interesting take on what a modern AR-180 would have evolved to look like. Will it satisfy the purist looking for an exact AR-180 reproduction? No. bit on this world awash with fire sale priced AR-15s of dubious pedigree Brownell’s BRN-180 is a nice option.
Brownells BRN-180 Upper Receiver Specs
- Type: Short-stroke piston-operated semiautomatic
- Caliber: .223 Wylde chamber handles both .223 Rem. and 5.56 NATO
- Capacity: 25-round detachable box magazine
- Barrel: Nitrided 16 in., button rifled 1:8 twist; threaded 1/2x28; 3-prong flash suppressor
- Overall Length: 32.7–36.7 in.
- Weight: 4.6 lb.
- Receiver: 7075 T6 aluminum; flattop w/1913 rail; reciprocating charging handle; polymer ejection port cover handguard 7075 T6 aluminum, free-floating, M-Lok
- Price: $799
- Manufacturer: Brownells, brownells.com