Howdy. I'm RC. This will be posted on Reddit's r/ar15 in addition to arf for your reading convenience.  

Bottom line up front: I like the upper.  It suppressed okay enough.  Recoil was nothing surprising.  Balance was fine. Accuracy may have been negatively impacted due to issues not directly related to the form and function of the upper assembly itself.

Photo of the weapon in question (parts still en route)


- BRN-180 upper
- Aimpoint PRO
- MBUS pro
- asr flash hider
- Form 1 Suppressor (Build specs in link)
- Burnproof handguard wrap
- Surefire SR-07
- Surefire UE tailcap
- Arisaka inline scout mount
- Arisaka m300 body
- Malkoff E1HT

- TM 80% lower
- cmmg parts kit
- Magpul K2
- Magpul trigger guard
- KNS picatinny adapter
- Jmac AB-8R
- sig folding mechanism
- Tailhook mod 1c
- lancer lm5 20 round magazine for the
- A E S T H E T I C

Final weights:
9lbs with a loaded 20 round mag and suppressor.

A prelude: in august of 2020 I conceived a bolt action setup to utilize my form 1 suppressor.  The goal was a Ruger American Ranch in 300 blk for a dedicated subsonic rifle to be built after the trump inauguration. However magpul took too long to bring the proper magazines to market for their hunter stock and Joe got elected. So that build got a bullet in its head.

HOWEVER

I also had the desire for a Virtus pistol as a truck gun.  I checked the prices and availability for a Virtus and felt my pp crawl back into my body.  Then I learned about the BRN-180 and thought hey, I could deal for a poor man's MCX.  So that's what I did. I cut an 80% I had laying around and ordered an upper second hand because I'm an impatient bitch.  The following is my experience with the system itself and not the process of cutting an 80% or building the lower because no one cares about that and there's plenty of guides. Regarding the accuracy of the upper I stress this is a sample size of one with a single type of ammunition and a single shooter who hasn't been behind a rifle in over six months.  

Quick features:
- suppressed and unsuppressed setting adjustable with the rear of a case (or quarter or screwdriver etc). Little window to show which setting you're on.



- Side charging
- Fully housed recoil assembly (read as no buffer tube needed)
- 10.5" 1/8 twist, 1/2x28 threads.
- Piston driven
- Compatible with AR15 lowers. Probably mcx compatible too if you're into that sort of thing.

Manuel of arms:

The first time you pick up a built BRN-180 you immediately feel like you're holding your trusty stoner rifle, but something definitely feels amiss as you run your hand along the top of your rifle and grasp aimlessly for a charging handle tab that isn't there.  You collect your thoughts and realize that like millions you've grown accustomed to a unique method of charging your rifle.

The BRN-180 hails from - well - the AR-180.  It's got a gooseneck looking charging handle and some knurling.  


Simple. Functional.  Very grippy. Directly seats into the carrier so it is reciprocating. It's going to be both your charging handle and your forward assist, not unlike other reciprocating handle systems.  Oh, and it's also your brass deflector.  Just FYI.  One neat thing is that this system charges super easy. I mean real easy. Like I can pull back with my pinky and get full travel with the hammer forward easy.  Smooth. Light feeling. A little run of oil on the slidy spinny bits and it's super clean.  

If you've ever held a trashcan gun you know that it doesn't have that oh so iconic charging handle right under your nose. Being a prominent swoopy bit, you have your charging handle on the right hand side.  Mikhail wanted you to use your right hand and hold with your left, but conventional wisdom says to roll left or roll right depending on if you want to go around your mag or your optic. The same applies to the BRN-180.  I think a neat feature in the future if they want to branch away from the pseudo-retro and treat it more like a new platform (similar to what the mcx is considered), a way to forward charge or even a left sided charging handle channel would be a neat upgrade. That said, left sided charging is likely infeasible as that is where the cam channel exists. But hey a man can dream. I personally prefer to reach around like I'm fishing for a promotion, but it's all based on the individual and how you train.

Over the top


Under and around


Lower controls are standard stoner, nothing fancy about it. Trigger goes bang. Mag release on the right. Ping pong paddle on the left.  Safety goes on and off at a 90 (or 60 or 45 if you're Gucci).  The lower is what you make of it. Brownells offers a retro style lower and a modern style lower with the picatinny rail in place of a receiver extension thread, but it's at your discretion.  I personally opted for an 80% lower paired with a KNS picatinny adapter, but there are a couple other options available.  The KNS was the most highly reviewed and it functioned as described*.

Something else unique about the BRN-180 is the lack of a buffer extension.  Consider the upper assembly and revisit the first photo in the thread.  The black part of my upper stayed black for a reason: this is a polymer molded around the two guide rods of the bolt carrier.  These rods sit above the bore axis and through the carrier, allowing for the total capture of the recoil assembly in the upper receiver.  This means you can build a weapon without a buffer tube.


The jmac AB-8R with a tailhook mod 1c is the brace I chose to run on this build. It's the most rigid option available for inadvertent shouldering and consistent touching of the cheek.  It's also AFT approved as of now and it's actually really nice.  It folds. It's all aluminum so it balances better. It sits still*. It does what I want it to.  The sig folding mechanism is probably the most robust folding mechanism available when it is available, so I recommend that system over say the sig folding braces or the SB folding braces.  Stronger springs, beefier mechanism.  One of the complaints of those braces is that they pop out of lock when fired. This did not.


Reggie report:

So today was just to zero my PRO and my Pro's.  Ammunition was IMI 855 purchased in 2018 shot off a rest from 50 yards for a 50-250 zero.  Minor breeze, cool day.  Hadn't touched a loaded rifle pistol in over half a year (I know, I suck. That will be apparent soon enough).  First round was unsuppressed and it tore a hole in my range backpack.  Not the round, the muzzle blast from the flash hider and 10.5" barrel.


Great. Gun short stroked and I forgot my can.  The short stroke was to be expected since it was in the suppressed setting and I didn't have a suppressor.  I toss on my form 1 suppressor. Short stroke.  "Well that's weird."  

Short stroke.
Short stroke.
Short stroke.

Maybe my suppressor isn't as high back pressure as I expected?  I turned it to the unsuppressed setting and it fired and cycled without issue. Locked back on open bolt. Did the things you expected it to do. Didn't feel overgassed either. Neat.

Recoil while suppressed wasn't bad at all. It was a smidge gassy, but from the ejection port alone and not from the rear of the receiver as one would expect with a standard AR upper.  Thanks PWS/FM/Brownells. Very cool. Again, this goes back to not having that gap where the charging handle traditionally is.  One possible advantage over the mcx if that's how you swing.

After I got my red dot in the ballpark I got my irons where I thought they would work.  Neat.

It was at this point that I showed myself incompetent with groups.  I could not get anything tighter than three inches at 50 yards (with and without the suppressor) with the RDS, and the best I was able to manage with irons was 1.5" at 50 yards. Here is a photo of my post zero grouping with the described ammo.


Not hot at all. I haven't shot in a while, this is to be expected I suppose.  However, as the range trip prolonged I noted my brace assembly becoming wobbly. The folding mechanism and the bar remained rigid, but the bolt holding the Pic rail to the receiver extension came loose. I did not use locktite and only used the German spec (Guutentight) to secure it.  As one might assume, this caused severe inconsistencies in cheek weld and head placement.  Naturally this can affect the accuracy of a shooter-weapon pairing. Eventually the rail segment's bolt had unthreaded to the point that I could spin the brace around 90 and my takedown spring shot out. I found it, thanks for asking, but I did not feel that I was able to fairly assess the brn-180 upper any further than that, and did not feel that I could enjoy the rest of my outing.



As soon as I came home I went to the Home Depot and bought some blue locktite. Brace interface is curing as we speak.



Final impressions:

With only 250 rounds through the rifle thanks to an assembly error on my part, I was unable to see if I was the reason accuracy sucked or if there were other confounding factors. I'm going to err on poor fundamentals and a less than ideal setup as when I forced myself into the pistol such as for my iron sight groupings, accuracy improved and my groupings tightened. However by the time I pulled my head out of my ass there was no way I would be able to get a consistent weld to the brace while using the dot.  I'd love to spend more time with this system especially suppressed since that is how it will live the rest of its days, but until ammo comes down a little in price that likely won't be the reality.  

For the few rounds I was able to put it through, I liked it.  I wanted something unique and I built basically the exact weapon I wanted. I feel disingenuous recommending it after so few rounds, so I won't make that statement.  However, if late Gen 1 range reports are any representation of the current platform (and I do believe they are) the weapon will be reliable due to its 180 heritage, respectively accurate, and suppress well due to its construction.  

Take one for a spin.  See for yourself.  It's a neat little platform that I hope continues to blossom.


Post notes:

So there's a few things to be cognizant of if you're going to do some of the things I’m doing.

1. the burn proof wrap will cover all the mlok slots. Not a big deal but this will impede ventilation.  Something to consider.

2. The brace setup I chose will strike the receiver despite the rubber bumper being present. The tailhook is barely too wide and hits when it hinges to the folded position. This can be buffered with a strip of Velcro (the loop bit, not the hoop bit)





3. I used grey rustoleum American accents primer. If you're going to paint your gun and run a QD muzzle device, install the device after you paint.  You cannot remove the handguard with a muzzle device wider than the gas block, which most ASR, Keymo, Griffin taper, yhm, etc will be. Not a big deal, just wrap a tube of paper inside the handguard and you'll be peachy



4. Locktite ur shit. My picatinny section on the kns adapter came loose and fucked my shit.  Locktite anything you're threading that's in line with the axis of the bore. It will shake loose if it doesn't have another mechanism to secure it like a taper face.

Thanks for taking the time and great write up. I saw the first picture and was like "hey, that kind of looks like a Virtus" so I say you accomplished your mission. The color looks good. I've been interested in a BRN-180 upper for a future build. I run PWS Mk111 Mod1 as my primary and love it, but there is something to be said about folding stocks/braces (especially as a pistol under a seat or in a bag).

When ammo prices come down in 5 years, please be sure to do a follow up

Pretty awesome. For my setup I owed a Tegra Arms polymer lower. I had the same probably with the KNS 1918 adapter but Instead of loctite, I used teflon tape to "fill the gaps". Believe it or not, it works and hasn't come loose either. Also, I decided to get a Stealth suppressor for minimal blowback but it's still in jail. Only been a couple months.

I’m glad I’m not the only one who had that issue.  Was definitely disheartening that I had to cut the session short.

Absolutely. I’m looking into vertex and other bag options to toss the pistol into as a truck gun.  Problem is that the nice bags all run around 150-200+.  Not the end of the world but I’d like them to be a little less up there.  

I’ll be sure to strap my accupower 1-8 on next time I have it to see what groups I can actually manage.

Nice review, thanks for posting.

I'm a big fan of the brn180, recently picked up a gen2 180s in 300blk and have run a gen1 16" in a few matches without issue - hope to get more rounds through both this year.

Currently running mine on aero m4e1 lower, but if I was doing a new build it'd go on one of those brn180m dedicated lowers

Yeah that’s probably the best option tbh. Less stacking and more stable.

October update:

Finally had the chance to go to the range again multiple times since this initial post and was able to get about 2-3 moa groups consistently with 855 ball.  Weapon handles very well suppressed and currently has a saker 7.62 as its dedicated suppressor as well as a sling and a hand/barricade stop. Balances very very well and has an extremely tame recoil impulse. Might end up repainting it with some ODG in the future when the primer on the lower finally turns to shit and needs to be repainted.

RC,

What adapter are you using to place the tail hook on the armbar?

Looks really clean and better than some of the other options i've seen and used.

Looks like a KNS adapter.

This.  KNS adapter **with** the flange.  Keeps tension on the takedown pin detent spring.

The tailhook clamps onto a round part that came with the arm bar.  They’re sold together (the arm bar and the tailhook adapter).  

I haven’t really seen the other options you’re referring to.

I can't decide weather I want the 16" or 18.5" upper.

If I were to get a long BRN it’d probably be the 18.5”. Especially if you’re not suppressing it.

I probably will be, once my surefire gets out of NFA jail.  Going to be ordering the upper in a few weeks.

A great review, thanks

I just picked up a 16” mod 2 upper
Going to use a 17 DM lower with the pic rail

In that case I’d go as short as reasonable.