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The AR-15 rifles are equipped with upper and lower receivers, usually crafted from heated aluminum (forged one). The AR15 upper is a simplified name of the upper receiver, which is necessary to protect urgent AR15 parts.
This review will show you the differences between uppers, which are necessary to be aware of in order to properly build an AR15.
Why do we need an AR 15 upper?
All parts of the AR15 rifle are interconnected. If you forget to put even a small detail, the whole unit won’t work at all. If you want to improve the accuracy, the upper receiver will help even more than the lower one, because the fired bullet or the loaded round operates in the upper receiver. The completed rifle weight and general performance are affected by the upper as well.
Table of Contents
- Best AR 15 Upper | AR 15 Upper Reviews
- #1 Aero Precision M4E1 5.56 Mid Barrel Complete Upper Receiver
- #2 Luth-AR AR-15 11.5in Lightweight Complete AR 15 Upper Barrel Assembly
- #3 TRYBE Defense AR-15 16in Complete Upper M-LOK, .300 BLK UPPER
- #4 Wilson Combat Billet AR 15 Upper Receiver
- #5 TRYBE Defense AR-15 Lightweight M-LOK Handguard with Full Rail
- #6 V Seven Weapon Systems – AR-15 Upper Receiver Lithium Aluminum
- #7 Aero Precision AR15 5.56 Complete Upper Receiver
- #8 SLR-B15 Billet Upper 5.56 Receiver SLRB-15-UPP 556
- #9 Stag Arms AR-15 A3 Flattop Upper Receiver Assembly
- #10 TRYBE Defense AR-15 16in Complete Upper M-LOK, .223 Wylde
- #11 ODIN Works INC. – AR-15 Billet Upper Receiver
- #12 Dark Hour Defense AR15 Billet Upper Receiver DHUPP
- #13 Precision Reflex AR-15 Flat Top Upper Receivers
- #14 Aero Precision M4E1 16in 5.56mm M4 Carbine Barrel Complete Upper Receiver
- #15 TRYBE Defense AR-15 Pistol 10.5in Complete Upper M-LOK, .300 Blackout
- How to Build an AR-15 Upper Receiver
- The Best Pick
- Budget Pick
Best AR 15 Upper | AR 15 Upper Reviews
#1 Aero Precision M4E1 5.56 Mid Barrel Complete Upper Receiver
This Upper is outfitted with feed ramp extension, anti-rotation tabs, constant top rail, scalloped rails, and improved milling construction for better gripping and visual attractiveness. The Upper Receiver Handguard Combo with Gen 2 improved handguard is designed for AR-15 A2 Flash hider and should be placed on the M-LOK Picatinny Rail. This barrel is listed as a mid-length one and is a government profile. The reinforced upper locks tightly into the typical M4E1 lower without wobbling. A BCG or charging handle doesn’t come with the upper kit.
#2 Luth-AR AR-15 11.5in Lightweight Complete AR 15 Upper Barrel Assembly
Lightweight barrels are crafted from Chrome Moly Vanadium (4150) with 6 Lands and Grooves, a 1–9-inch RH Barrel twist joined to an A3 Flattop receiver, which comes with a charging handle, bolt carrier, ejection port cover, and forward assist. The upper is topped off with a low-profile gas system (.750 diameter Gas Block and Carbine-length Gas Tube), 9-inch Palm Handguard with a Picatinny top rail, and KeyMod slots.
#3 TRYBE Defense AR-15 16in Complete Upper M-LOK, .300 BLK UPPER
This versatile Complete Upper comes with everything (a bolt carrier group, a 15-inch M-LOK Freefloat Rail, 5R Rifling, an A2 Flash Hider, a 1:8 inch Twist, Mil-spec Charging handle, Nitride BCG) to install straight to a lower receiver and it’s ready for shooting. This 4140 CMV black Anodized Nitride barrel shows good results in groupings out to 75 yards with about 1.25 in MOA among groups.
#4 Wilson Combat Billet AR 15 Upper Receiver
This upper is a next-generation precision tactical firing platform, which matches well with Wilson BILLet-AR lower receivers, standard Mil-Spec forged AR-15 GI lowers or and any standard AR barrels. It is outfitted with a Picatinny top rail, shell deflector, a precise undersized bolt raceway for smoother chambering, tougher receiver walls to minimize shooting flexibility. This upper is CNC machined from aerospace aluminum (7075-T6) billet stock, covered with Mil-Spec hard-anodized black. The 458 SOCOM cartridge is appropriate for hunting medium to large game, bullets in the 250 – 400 grain weight range feature huge killing power.
#5 TRYBE Defense AR-15 Lightweight M-LOK Handguard with Full Rail
The handguards are equipped with a full-length Picatinny rail on the top for secure mounting scopes, red dots, and other optics, coming with mounting screws and a barrel nut. The TRYBE Defense crafted these AR-15 Lightweight M-LOK Handguards from sturdy aluminum (6061-T6). There are eight models with 4 options of handguard length, available in Flat Dark Earth and Black colors.
#6 V Seven Weapon Systems – AR-15 Upper Receiver Lithium Aluminum
The Ar-15 Upper Receiver is crafted from an advanced alloy of Lithium and Aluminum (billet 2055) with Hardcoat Anodized (type Iii). Enlightened 2055 Upper should be Minor fitted to the Upper rail to be compatible with Geissele Mk8 Rails. It’s recommended to lubricate all installed Springs, Pins, Screws, and parts with quality oil or grease.
#7 Aero Precision AR15 5.56 Complete Upper Receiver
The Complete Upper Receiver is combined with the ATLAS handguard allowing the AR15 build to be more modern and lightweight due to the Forward Assist removing. This upper receiver with M-LOK mount type is equipped with Mid-Length Barrel and A2 Flash Hider.
#8 SLR-B15 Billet Upper 5.56 Receiver SLRB-15-UPP 556
The SLR offers Upper Receiver with Mil-Spec dimensions and Mil-Spec Hard Coat of Type 3. These uppers are made of Aluminum Alloy (7075 Billet) with Matte Black Finish. The assembly comes with Black Billet Shell Deflector and Door installation.
#9 Stag Arms AR-15 A3 Flattop Upper Receiver Assembly
The Stag Arms developed A3 Flattop Upper Receiver with dust cover and installed forward assist for mounting on the Picatinny Rail of the AR Platforms. This Assembly is forged with Black hard-coat anodizing (type 3), complying with mil-spec standards.
#10 TRYBE Defense AR-15 16in Complete Upper M-LOK, .223 Wylde
This AR-15 Mid-Length complete upper is outfitted with a 15-in M-LOK Freefloat Rail, Mil-spec Charging handle, an A2 Flash Hider, barrel with 5R Rifling, and a 1:8-in Twist. The upper receiver barrel is made of Stainless Steel (416R) with a Black Nitride BCG finish.
#11 ODIN Works INC. – AR-15 Billet Upper Receiver
The Odin, taking into account modern trends, reduced weight and bulk to make the rifle building with Billet Upper Receiver sleeker and thinner for convenient carry still delivering great performance. These uppers are equipped with a trimmed-down brass deflector.
#12 Dark Hour Defense AR15 Billet Upper Receiver DHUPP
These Upper receivers are outfitted with a 1913 top rail and extended feed ramps, designed for AR15 platforms to ensure durability and accuracy. The uppers are manufactured from Aluminum (7075 T6 Billet), covered with mil-spec hard-coat anodizing (Type 3), with Dark Hour Defense logo.
#13 Precision Reflex AR-15 Flat Top Upper Receivers
AR15 Flat Top uppers are crafted of forged aluminum (7075 T6) with Black Hard Coat Anodized, complying with Mil-spec standards. This upper receiver is equipped with forward assist and dust cover.
#14 Aero Precision M4E1 16in 5.56mm M4 Carbine Barrel Complete Upper Receiver
The Aero Precision engineered M4E1 Complete Upper receiver with Scalloped Rails, Anti-Rotation Tabs, continual Top Rail, and Feed Ramp Extension, but without BCG and Charging Handle.
#15 TRYBE Defense AR-15 Pistol 10.5in Complete Upper M-LOK, .300 Blackout
This upper barrel is made of 4140 CMV, covered with Black Nitride BCG. The AR-15 complete upper receivers are equipped with an A2 Flash Hider, a bolt carrier groupб a 10.5-in M-LOK Free Float Rail, a Mil-spec Charging handle, a barrel with 5R Rifling, and a 1:8-in Twist.
How to Build an AR-15 Upper Receiver
An armorer’s wrench or the barrel nut wrench (for a proprietary foregrip), a vice, a torque wrench, some grease, and a little Loctite (for the barrel nut) will be necessary.
- Install the barrel in the upper receiver, thread on the barrel nut onto the upper, and tighten down to 35-65 ft-pds.
- Then fix the gas block and tube assembly slide the handguard over the barrel nut (Loctite gives added grip of the barrel nut with the knurled surface).
- Align the rail with the receiver and put the mounting screws in the drilled holes, tightening them down to 50 pounds.
- The installation for an assembled receiver will be quicker than a striped one (no need to install the forward assist and ejection port cover).
AR-15 assembled Upper Receiver Build
- A barrel nut for the gas tube alignment tabs and a set screw-based gas block are included.
- Before tightening the handguard up, check the gas tube coming out straight.
- Thread the barrel nut on before the gas block allows for handguard tightening.
- Some barrels are dimpled, which is convenient to pair them up with a set screw kind of gas block instead of the clamp one as we do in stripped receiver mounting.
- After tightening the holes with the two included rods the handguard stayed put.
- It’s recommended to use a screwdriver through the larger ports or use straight edges for a wrench.
Stripped receiver mounting
- First, an upper receiver should be placed into the vice block and take the two pieces of the forward assist -FA (its tooth should be faced in towards the receiver), duly orienting them and start the roll pin with a punch. It’s possible to use the hammer softly, tapping in the pin enough so the FA cannot come out.
- Then fix the ejection port. The pin should have installed the C-shaped snap ring. Otherwise, be attentive not to lose this small part while installing it.
- Before twisting the spring 180 degrees, put the ejection port, slide the hinge pin. Then push the rod through in the empty area.
- Mount the barrel with the oiled index pin, fitting into the receiver, and place the nut onto the barrel.
- The proper seating between the handguard surfaces procedure depends on setting the torque to 35 ft-lb and loosening, doing in this way a few times in a row.
- If you have a new handguard, a gas tube alignment isn’t required, but older versions of many handguards do (the gas tube should fit on straight both with the gas block and into the barrel nut index “U”).
- Get the gas block and gas tube out. Start the roll pin, finishing it. Slide on the gas tube over the barrel, use a .025 in space to move the block back for the best fit.
- Set the wheeler torque wrench to 35 in-lb (or according to the gas block instructions) to make the torque even.
- Install handguard mounting hardware, fitting it to the receiver, align duly, the indexing pin should be completely flush at the bottom near the screws.
- It’s better to use a crush washer and its smaller side should be towards the barrel.
- Align both top holes and the big ports on the side to vent the gases majority to the side and some to the top to counter muzzle rise.
- The last step is to lube up the charging handle and BCG.
There are two builds, which differ in a way of barrel, gas blocks, and handguard mounting: a striped one, which comes with forward assist and ejection port cover, and the assembled one. The second build is an SPR (special purpose rifle) that delivers more accuracy, meanwhile, the first one provides weight and speed. The longer the barrel, the more the round’s velocity. The intermediate length (between middle and rifle) ensures a softer shot, and the reliable chamber gives more accuracy.
The Best Pick
Aero Precision M4E1 16in 5.56mm M4 Carbine Barrel Complete Upper Receiver
This improved upper with integrated handguard features quality craftsmanship and plenty of room for optics, lights, and hand stops.
Wilson Combat Billet Upper Receiver
The upper provides enhanced feeding and recoil dynamics, the ability of gas volume adjustment, and maximum accuracy due to the smooth side profile without forward-assist.