Expo Arms has recently gotten into the AR-15 upper receiver market. They have a few options for pistols, SBR’s, and standard AR configurations. This particular upper is their Patrol series with a 16” barrel and A2 flash hider. If you didn’t know, Expo Arms is the in-house brand for Primary Arms and is sold exclusively through them.

The Expo Arms Patrol Series is an everyday use AR-15 barrelled upper receiver. These do not come with a bolt carrier group (BCG) or charging handle. However when you order the upper, Primary Arms gives some drop down menus with discounted add ons, such as a BCG. The Patrol Series comes with a bunch of good specs: A 5.56 chamber, 1:7 twist nitrided 4150 cmv barrel, mid-length gas system, A2 flash hider, T-marked upper receiver, and a 15” M-Lok handguard.

Barrels are an important part of any AR system. On 16” barrels, like this one, I like mid-length gas systems. They are smoother feeling and put less wear on components then a carbine length gas system. Being that the barrel is also salt bath nitrided, it will have a good lifespan and keep corrosion away. Expo Arms uses a SOCOM profile on the barrel. I like the profile as it gives strength and consistency without being heavy. Of course the muzzle is threaded and comes with an A2 flash hider installed. The barrel consistently shoots under 1 MOA for me with 69 grain match rounds.

Expo Arms uses their own T-marked upper receiver. This is a standard forged version made from 7075-T6 aluminum. It has a round style forward assist and a standard mil-spec port door. The whole upper is nicely machined and anodized.

To cover the barrel, and give you something to hold onto, is the 15” M-Lok handguard. This is a very nice, useful, no frills handguard. It runs a full top rail that is not sharp. The sharp parts of the rail have been deburred slightly. Along the other portions of the handguard are M-Lok slots. These M-Lok slots are every 45 degrees around the handguard, not just the standard of every 90. It’s a clamp on style handguard, but also has some anti-rotation tabs to keep it from rotating. I’ve never had a problem with these style handguards rotating on me, but the tabs are a nice addition. I really liked the Expo Arms handguard, I’d even consider it as a stand alone item.

If you’re looking for a good quality AR upper, the Expo Arms Patrol series might just be it. It has a lot of nice features for the price. In fact, I am still amazed at the 0.75” group I shot with it. Definitely go check out the Expo Arms series of stuff over at Primary Arms.

Firearms Insider Reviews - 8 Key Points

Claim to Fame:

Quality 5.56 AR Upper receiver at a fair price

Target Market:

Anyone wanting a 16” AR upper

FNBs (Features & Benefits of this product):

7075-T6 forged aluminum MIL-SPEC upper
5.56 NATO chamber
T-Marked
16" Patrol Series Nitride barrel
41V50 Chrome Moly Vanadium Steel barrel
SOCOM barrel contour
Mid-Length Gas System
1:7 Twist Rate
15" Expo Arms Patrol Series M-LOK Handguard
A2 Flash Hider
No BCG or Charging handle

What other aesthetic options or finishes are available?

Various

What others are saying?:

Nothing as of publishing

Link to other reviews:

Nothing as of publishing

Price point:

MSRP = $349.99

Retail = Check Primary Arms for sales

I need it now! Availability:

Primary Arms

Our Rating:

Pros:

Nitride Barrel
T-Marked upper
M-Lok handguard
Full top rail
Accurate

Cons:

Doesn’t come with BCG or CH (options are available)

Score: 8.50 Great

Favorite Link: Walker Defense Nero Review

Expo Arms, in collaboration with Forward Controls, introduced an extended muzzle brake for use with certain Dead Air silencers. This brake uses the “Keymo” mounting option and is for use on .223/5.56 suppressors, but it will also work on any .223/5.56 AR style rifle as just a normal muzzle brake.

The extended Keymo muzzle brake has 1 port or chamber. Don’t let the 1 port fool you, as the muzzle brake works very well at reducing recoil. Because it’s for use with .223/5.56, it is threaded for the standard ½-28 found on those rifles. Expo/FC’s gave the brake a .30 caliber bore to reduce some noise. They also gave the ports a flat profile. The flat profile directs gasses straight to the side, so that people behind, and to the side of the shooter get less noise and concussion. Being that it is a muzzle brake, it is still fairly loud.

Having the Keymo mounting surface makes it useful for those with certain Dead Air suppressors. The Keymo system mounts the suppressor on a quick on/off taper system. The taper helps repeat a consistent bore to suppressor mount, along with making a tight seal. An advantage to using this type of muzzle brake, with a suppressor, is that the muzzle brake will reduce the forces against the blast baffle inside the suppressor. I however, do not have a Keymo suppressor, so I didn’t get to try this part out.

Even if you don’t have a suppressor, the Keymo muzzle brake is useful for other reasons. Since this is an “extended” muzzle brake, it is long enough to take a 13.9” barrel and make it 16”. Of course for legal reasons, the muzzle brake must be pinned and welded, unless it is going on a pistol or SBR. Expo/FC already machined in a hole for the pin, if one chooses this route.

I have been using the single chamber brake on a 16” AR. Yes, it adds a little bit of length, but it didn’t seem to bother me any. I was really surprised at how well the single port did it’s job. The brake made the rifle shoot flat. I can shoot the AR quite fast with this Keymo muzzle brake. If they made this brake without the Keymo mounting, I would consider using it on a 13.9” barrel that needed a pinned and welded brake.

The Expo Arms Keymo brake is only available at Primary Arms. Not that this is a problem, as Primary Arms has a lot of quality gear. The Expo Arms/FCD Keymo brake is top notch, even if you don’t have the Dead Air suppressor to use it with.

Firearms Insider Reviews - 8 Key Points

Claim to Fame:

Extended length muzzle brake for use with the Dead Air Keymo mounting system

Target Market:

Those wanting a Keymo brake that when pinned will make a 13.9” barrel extend to a legal 16”

FNBs (Features & Benefits of this product):

2.7" Overall length
Single chamber design
Pin and weld to 13.9" barrels to meet 16" requirements
1/2x28 threaded for 5.56/.223
.30 cal bore to reduce blast
Dead Air Keymo mount
4140 steel
Properly heat treated
Salt bath nitride finish

What other aesthetic options or finishes are available?

none

What others are saying?:

5/5 stars at Primary Arms

QUALITY PIECE OF KIT

Just received this Expo Arms / FCD muzzle device and installed it today. First I would like to note that when torqued to spec on my barrel, no shims we’re needed as the device properly indexed off the bat! Second, the quality of materials and finish seem to be on par with Dead Air’s own devices. Third I’d like to state that the overall length of this device makes it cross-compatible with both Dead Air’s KeyMo and KeyMicro mounting systems! Will be putting a lot of rounds through this device in the future to see how it will hold up.