AR style pistols chambered in handgun cartridges like the ever-popular 9mm are becoming increasingly common.
As with everything AR, the possibilities for customization are endless. Finding the best 9mm upper receiver can be tough, but we've got you covered. Read on.
At a Glance: Our Top Picks for 9mm AR Upper
- OUR TOP PICK: PSA Gen4 16" 9mm Nitride 1/10 13.5" Lightweight M-lok Railed Upper - With BCG & CH
- RUNNER-UP: Foxtrot Mike Products - AR-15 9mm Upper Receivers M-lok Assembled
- BEST BUDGET OPTION: FM Products Monolithic 9mm Upper Receiver
Comparison Chart of the Best 9mm AR Uppers
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What Are The Components of a 9mm AR Upper?
AR upper receivers chambered in 9mm have all the same components as their standard counterparts, just slightly tweaked to work with the non-standard round. Assuming we're talking about a complete assembled 9mm AR upper, there will be a full set of components integrated into the aluminum receiver body itself.
Foxtrot Mike Products ultralight 9mm AR Pistol
First, there will be a barrel with a gas system and handguard. Inside, there will be a bolt carrier group. Charging handles come in a number of varieties, including classic M4 and non-reciprocating. Forward assists are less common on 9mm uppers than they are on standard AR receivers.
A dust cover is also an optional item. Very few 9mm uppers have carry handles. Rear sights are usually not included, while front sights are hit and miss. Gas block front sights are less common than on standard ARs.
Are All 9mm AR Uppers The Same?
There are a wide variety of customization possibilities when selecting a 9mm AR upper receiver. This is why building such a firearm can be so rewarding. Smooth side receivers are lower profile than standard and lack the protrusions common on ARs like a shell deflector and forward assist.
These features are less useful with the 9mm, anyway. Upper receivers come either forged or machined. There is an idea that forged receivers are stronger because the forging process slams the molecules of the aluminum alloy into alignment.
PSA Gen4 16" 9mm Nitride 1/10 13.5" Lightweight M-lok Railed Upper
However, machined receivers are CNC cut from billets of aluminum alloy that were originally forged anyway. Some are monolithic or mimic the monolithic style. This means that the handrail integrates seamlessly with the upper. This can be more rigid and accurate, and also looks a lot cooler.
However, the main distinction among 9mm AR upper receivers is that between complete uppers and stripped ones. The stripped variety gives you the opportunity to customize all the components you use to build your firearm. The complete variety, on the other hand, are ready to drop into your lower immediately—cock, lock, and rock and roll.
What Makes a Great 9mm AR Upper?
To some degree, the best 9mm AR upper will depend on your preferences. The first thing to look for is an product made by a reputable, well-established company. Even specific models can be more proven and esteemed than others.
The particular alloy of aluminum used to manufacture the receiver is less crucial with a 9mm upper than with standard ARs thanks to the lower pressures. Compatibility is a major concern when choosing one; some models are calibrated to work with the widest variety of lowers, but still require verification.
Others work best with lowers from the same company. Reliability and wide compatibility make a desirable combination. If your upper is complete, the quality of the components used will determine how reliable and accurate it will be. A quality barrel is the most crucial component.
Review of the Best 9mm AR Uppers
With so much to think about, choosing the best 9mm AR upper receiver can be a real headache. Here is our list of the best options on the market today:
Best Overall:
PSA Gen4 16" 9mm Nitride 1/10 13.5" Lightweight M-lok Railed Upper - With BCG & CH
Pros
Cons
Palmetto State Armory is one of the largest retailers of firearms and firearm accessories in the US of A. This puts them in the enviable position of having an endless supply of market data. They know exactly what products are popular, which ones come back for warranty and which ones just work.
They use this incredible wealth of knowledge to produce many of their own firearms and firearm components. This outstanding upper is a great example. The specs on this are generally what you would expect.
It has a 16-inch chrome moly steel barrel with a 1:10 twist rate. The barrel has been nitride treated for exceptional durability. It comes with Palmetto State Armory's own lightweight M-LOK free-float handguard. At the end of the barrel sits a birdcage-style flash hider just for the 9mm round.
The upper itself is made from a billet of standard 7075-T6 aluminum alloy, which has been hard coat anodized for extra dependability. The slick side upper is manufactured domestically. The bolt carrier group is PSA's 4th generation hybrid 9mm BCG. This is a great option from one of the most reliable brands out there.
Bottom Line
This is a fantastic option. The top features of this product are the chrome moly barrel, the M-LOK handguard and the slick-side design. You will not regret getting one of these uppers.
Runner-up:
Foxtrot Mike Products - AR-15 9mm Upper Receivers M-lok Assembled
Pros
Cons
This is a fully assembled upper receiver that is ready to drop into any compatible lower that works with Glock mags. It has a full-length Picatinny top rail and a handguard with plenty of M-LOK mounting slots. This gives you loads of space for mounting your favorite optics or other accessories on some of the most widely compatible rail systems out there.
Foxtrot Mike's unique design for the connection between the upper and the handguard guarantees that your barrel nut will always stay tight. The barrel on this unit is made of top of the line Melonite 4150 carbon steel. It has been button rifled with a 1:10 inch twist rate.
The bolt carrier group also has a hard Melonite finish for maximum reliability. It is designed to work flawlessly with a wide range of lowers and fire control groups. It should also work with even the most bargain basement ammo that you can find.
The charging handle is ambidextrous and non-reciprocating. This is a great upper for reliable and compatible shooting. Not only does it work great, but it also looks pretty sharp.
Bottom Line
The top features of this upper are the M-LOK handguard, the compatibility with bad ammo and the unique handguard attachment design. This is an unbeatable option.
Best for the Money:
FM Products Monolithic 9mm Upper Receiver
Pros
Cons
There is a reason that Foxtrot Mike has garnered multiple spots on our list. They have a great reputation and offer incredibly high-quality products. They back this up with a great limited lifetime warranty.
This monolithic-style upper gives you a mean, sleek look. The upper receiver itself and the handguard blend seamlessly into one slick unit. Not only does it look wicked, but Foxtrot Mike's proprietary interlocking system between the upper and the handguard also ensures that your barrel nut will never come loose.
The barrel nut is machined from steel and installs with standard crescent wrenches. The seven long rows of M-LOK slots on the handguard give you plenty of space to mount your favorite accessories. The handguard mounts to the barrel nut with eight extra strong stainless steel screws. The handguards come in your choice of 8.5, 10.5 or 15-inch versions.
This upper has an ultra slim and low-weight design. It is designed and manufactured right here in the USA. A dust cover and case deflector are included. Instead of an M4 charging handle, this unit has an ambidextrous non-reciprocating forward charging handle.
Bottom Line
The best features of this 9mm AR upper are the cool monolithic design, the M-LOK handguard and the advanced charging handle. You will have a lot of fun with this unit.
Best Complete Upper:
PSA 16" 9mm Nitride 1/10 15" Lightweight M-lok Railed Upper With Hybrid BCG & CH
Pros
Cons
Palmetto State Armory is a company that we can't stop talking about. Their solid designs and manufacturing always come at a competitive price and their products are also some of the most reliable that you will find anywhere.
This innovative 9mm upper is compatible with both Colt and Glock style magazines. As with so many uppers from PSA, this unit comes with a 16-inch chrome moly steel barrel. This one has a 1:10 inch twist rate. It is nitride treated for great durability.
The barrel is paired with a 15-inch lightweight M-LOK free-float handguard. At the end of the barrel, there is an A2-style birdcage flash hider. The upper itself uses employs a slick side design constructed of 6061-T6 aluminum alloy. It is hard coat anodized as you would expect and made in the USA.
It fits best with Palmetto State Armory lower receivers designed to use Colt or Glock 9mm mags. Each upper is assembled to order before being rigorously tested. A standard bolt carrier group and charging handle are also included. This is a great, reliable choice for building a 9mm AR pistol.
Bottom Line
Palmetto State Armory always impresses with its value for money. The best features of this upper are the M-LOK handguard, the great barrel, and the testing regime. For a no-nonsense option that will last a lifetime, you can't go wrong here.
Best Upper Receiver:
GUNTEC USA AR-15 9mm Dedicated Billet Upper Receiver
Pros
Cons
Guntec USA is based in Scottsdale, Arizona. The company has been engineering and producing tactical weapons and accessories since 1989. They have enjoyed numerous high-level contracts with various branches of the armed forces and law enforcement.
All of their products are produced domestically at their facilities in Arizona. This upper receiver has a slick and mean-looking slab-side design. This also makes it a bit handier and lighter than many other options out there.
It has been manufactured from a billet of 6061-T6 aluminum alloy. You may be surprised that it doesn't use 7075, but don't worry, the lower pressures of the 9mm cartridge make this alloy more than sufficient. It lets Guntec give you extra features for a lower price with practically no tradeoff.
The top rail is a classic 1913 Picatinny for the widest range of compatibility with sights and other accessories. The hard coat anodizing meets or exceeds the MIL-A-8625 Type III specification. This upper is designed to pair with any 9mm lower receiver from any brand. This is a slick and handy little unit that looks as mean as hell.
Bottom Line
This is an outstanding option for a stripped upper. The top features of this option are the slab side design and the broad compatibility. The standard Picatinny rail is also handy.
Best Side Charging Upper:
Foxtrot AR-15 9mm Complete Side Charging Upper - 7"
Pros
Cons
Here we are with another entry from Foxtrot Mike. The man may have a taste for ballroom dancing, but his uppers don't mess around. This is one company that is known to stand behind its customers like no other. Buying Foxtrot Mike is kind of like joining a family.
This upper has been designed from square one to be innovative and cutting edge. Instead of a classic M4 charging handle, it has an ambidextrous non-reciprocating forward charging handle in a folding, paratrooper style. The monolithic look of the upper is reached through the use of Foxtrot Mike's proprietary interlocking mechanism between the upper and the handguard.
This guarantees that your barrel nut will not come loose. The free float handguard has a veritable sea of M-LOK slots for mounting all the accessories of your dreams. The barrel is only seven inches long and made from rough and tough 4150 chrome moly vanadium steel.
A special Foxtrot Mike blast diffuser is included. The upper itself is machined from 6061-T6 aluminum alloy, plenty tough enough for the 9mm round.
Bottom Line
Foxtrot Mike is an unbeatable company in the black rifle market. The top features of this upper are the customer support, the pistol-length barrel, and the unique charging handle. This is a fantastic option that will provide a lifetime of service.
Conclusion
An AR rifle or pistol chambered in 9mm can be one of the most fun and cheap to shoot guns in your arsenal. No matter what your tastes are, we are sure that you will find the best upper receiver for your needs on our list. Have fun and shoot safe!
