If you want to create a unique AR-15 rifle that meets all of your expectations, you won’t do better than building your own. One of the most important components you’ll need are your receivers, and today we’ll be focusing on the upper.
Typically, the parts used to make the guns you can buy directly from the shelf of a store are outdated, clunky and flawed; instead of finding that out the hard way, take the opportunity to learn about what you need and get it for yourself.
We’ve highlighted five of the best, most well-received upper receivers for building an AR-15, reviewed and favored by fellow firearms fanatics, to make finding the parts you need as simple and straightforward as possible.
Should you be new to the art of building your own gun, or just looking for a refresher lesson, check out the Buyer’s Guide, which dissects and defines the key features of a standard AR-15. It also tells you exactly what to look for in a quality upper!
Those with remaining questions might find the answer in a set of commonly received FAQs, where we’re providing the information your fellow customers have also been looking for as part of their search, in the hopes of helping you through yours.
Looking For The Ultimate Upper? Here’s Our Top Pick:
OUR TOP PICK
OUR TOP PICK
Marvellously machined from 7075 aircraft grade T6 aluminum, Aero Precision’s stripped upper receiver has superior strength.
Coated with a type 3 hardcoat anodized finish, you’ll be hard pressed to find better wear resistance.
Compatible with all military spec AR lowers and standard components, it features M4 style feed ramps for faster, smoother ammo replenishment.
Despite being a more economical option for your custom build, it doesn’t skimp on the finer details.
Easy enough to install thanks to a flawless finish, the pinholes are perfectly aligned; attaching your other components is a simple process.
Don’t worry about rattling, as this upper receiver should sit perfectly flush with its lower counterpart.
For those trying to mix their design up a little, it’s available in Black, Cerakoted OD Green and Cerakoted FDE/Desert.
If you opt for classic black, you can request laser-engraved T marks and even an American flag right there on the Picatinny rail.
Customer reviews demonstrate that amateur builders and seasoned gun pros alike appreciate the craftsmanship of Aero Precision products.
Provided you have all of the required tools for assembly, there’s very little to complain about.
- Constructed from aircraft grade aluminum - impressive longevity
- Excellent fit with all standard mil-spec components
- Multiple colors to choose between
- Additional etching is a nice touch
- Some reviews suggest the laser etching is not particularly deep, meaning it can rub away after just a few uses
Machined to perfection, the Upper Advanced Receiver from Lantac USA has an ultra-smooth proprietary bore.
With surprisingly less bolt carrier friction than your average upper, it has the silkier actions of a much more expensive receiver.
Composed of billet 7075-T6 aluminum paired with MIL-SPEC Type III Class 2 hard coat anodized finish, this is a component worth investing in.
Also utilizing the feed ramps of an M4, you’ll struggle to find a smoother option.
Thanks to their patented SMOOTHCAM system, featuring a low friction cam pin with a blended cam recess and domed head, every single component of this upper has been designed with the sole purpose of reducing internal wear and overall friction.
Speaking of cam pins, it’s machined from 14-4 PH stainless steel that’s been further hardened to H900 and polished to perfection.
It can be inserted into any bolt carrier as is - no need to remove the gas key due to a cleverly made circular head.
Made and distributed in the heart of the USA, Lantac are a manufacturer you can depend on, producing accessories for AR-15s of only the highest quality.
This lightweight, 8.8 ounce receiver is testament to those impressive products.
- Impressive quality, machined from aircraft standard aluminum
- Specialist SMOOTHCAM pin system
- Anodized mil-spec coating for an impressively hard-wearing upper
- Made in the USA
- Similar specs to more affordable receiver above
Providing the perfect match for an N4 receiver, the Rifleworks Upper Receiver is machined from billet aluminum; customized by Noveske to create a unique look, it’s still compatible with all mil-spec AR-15 components.
Offering improved corrosion resistance when compared to its predecessors, the type III hard coat anodizing process results in an upper that withstands plenty of wear and tear. It’s a suitable improvement that makes an excellent addition to any AR-15.
If you like to stand out from the crowd, their adjustments to the part’s external geometries offer a refreshing take on the design of an upper, but won’t compromise your ability to pair it with components from more traditional manufacturers.
Dedicated to the provision of AR-15 receivers, platforms and handguards in a wide range of calibers and configurations, Noveske has been making quality gun accessories since 2001. That’s two decades of valuable experience!
Featuring a forward assist for those who appreciate a nod to the original design, there’s also a flat top, which lets the user mount their optics at a lower level for reduced footprint overall.
If you want a more streamlined AR-15, look no further.
- Made from quality 7075-T6 Billet Aluminum
- Withstands years of use with the hard coat type III anodizing
- Compatible with all mil-spec AR-15 components
- Classic Noveske cross engraving
- Those who prefer to stick with what they know might not appreciate the flat top design of this upper receiver
Although on the more expensive end of our list, this matched receiver set from Fortis Manufacturing was produced using the highest quality of materials available.
Unrivaled machining technique means every Fortis product will meet your demands.
Attractively machined from a 7045-T6 aluminum billet, the impressively durable set has been finished with a rich black Mil-Spec type III anodized coating.
Corrosion and scratch resistant, you’ll appreciate how polished and pretty the pair will stay.
Building your own custom rifle has never been easier or more satisfying; the receiver tensioning screw and flared magwell with serrations make life a whole lot easier. Loading up your ammo takes half the time!
If you appreciate the little touches, this is a company you can depend on. Features like the oversized trigger guard for added protection, and a T-marked M1913 Picatinny rail for easily adding your optics, are sure to please you.
Likewise, you’ll enjoy the embossed Fortis shield and logo, offering a clear sign of quality.
Made in the USA, each and every pair has been stamped with this design, openly declaring their superiority against competitors.
- Thoughtfully constructed with 7075-T6 aluminum
- Durable pair - upper and lower receiver, ensuring a perfect fit
- Mil-spec hard coat anodizing, for long lasting protection
- Made by Fortis in the USA
- Costs more, given the upper and lower come as a set of two
Precision machined to match any mil-spec lower, this upper receiver from Cross Machine Tool promises ultra precision.
Machined from 7075-T6 aluminum, on a five axis machining center, the highest possible attention to detail is easily achieved.
Boasting superior strength and rigidity, the UPUr-4 has been designed for increased performance and improved function.
Hoping to provide an advanced, contemporary appearance to the traditional AR-15, it’s ideal for any builder looking for an upgrade.
An increased wall thickness, alongside the mil-spec type III, class II hard coat anodized coating, makes for a stronger, more rigid firearm overall.
Weighing only 7.5 ounces, it doesn’t compromise on sleekness in spite of its solid style.
Optics are easily attached using the 1913 Picatinny rail flat top, and the engraved T numbers are a helpful addition.
A machined dust cover port also assists in protecting your firearm’s internal components from potential damage.
Protected by a lifetime warranty against manufacturer defects, Cross Machine Tool ensures that every customer will be satisfied with their purchase, even those that arrive with faults.
Especially at this price, it’s a component you won’t regret buying.
- More affordable than other options, retaining quality
- 65% stronger than the standard 6061 aluminum receivers
- Compatible with all mil-spec parts
- Lightweight at only 7.5 ounces
- Does not feature forward assist or shell deflector
Best AR-15 Uppers Buying Guide
Anatomy of an AR-15
Please be advised this is a simple breakdown and not an instructive guide on building a gun - seek out a more thorough explanation if you need assistance on putting one together!
Upper Receiver: Let’s start with the part we’re checking out today! Rather than serve a purpose, the UR contains your bolt carrier and charging handle, as well as holding the barrel and forend.
Barrel: Typically 16 inches long, if not more, this is the shooting tube wherein the rapid expansion of gases causes your bullet to fire once the trigger is pulled.
Gas Block/Tube: In order to operate, the gas block and tube are connected to your upper receiver - this is where the gases that push your round out come from!
Bolt Carrier: Containing several key aspects of your firearm, including the firing pin, cam pin, bolt, extractor and gas key, this is responsible for loading, firing and ejecting rounds successfully. Buy the group pre-assembled or get individual parts!
Charging Handle: Serving to move your bolt carrier (and all its tiny parts) to the rear of your firearm when you need to replenish your bullets or remove a blockage, just pull on this handle and pop out any faulty shells.
Rail System/Handguard: Keeping your hands safe from the barrel once hot, as well as allowing you to add additional accessories such as sights, lasers, flashlights and optics, the length of this part correlates directly with the size of your barrel.
Ejection Port Cover: When this port is closed using an EPC, you ensure the bolt carrier and upper receiver both stay clean and free of debris.
Muzzle Components: To enhance your shooting experience you might use compensators, muzzle brakes or flash hiders on the rifle’s muzzle, improving not only your efficiency, but accuracy too.
Lower Receiver: The part that is widely recognized as “the actual firearm” as opposed to being a separate component, you’ll find lower receivers are legally controlled to a much more serious degree. Your AR-15’s serial number is found here!
Trigger and Hammer: What’s a gun without a trigger? Available in different sizes and weights, you’ll find a set that suits your preferences after some trial and error.
Buffer/Tube/Spring: A vital part of the firearm’s recoil system, the buffer absorbs plenty of impact from the kick of shooting, whilst slowing down the action in general and preserving your gun’s overall condition.
Butt Stock: Resting on your shoulder, this part varies in shape and size and determines how comfortable your shooting experience will be. They come in collapsible and fixed variants, each with a set of pros and cons.
Foregrips/Pistol Grips: Ensuring that your trigger hand is always strong and steady, these mean you’ll always have a tight hold on your gun, and the better yours is, the more of an advantage you’ll have over potential assailants.
Uppers: What To Look For
Where a complete or assembled upper usually includes the barrel, bolt carrier group, charging handle, handguard, ejection port door and dust covers, a stripped upper receiver is the very basic piece of metal.
You want to ensure that whatever upper you go for, it is of a high quality, and the forged designs are always better than machine made counterparts. Some manufacturers will utilize both techniques for the best of each style.
For greater accuracy, consider an upper that is built with a free floating handguard, as opposed to the drop-in variety, which are also referred to as rails. This is only important if you’re planning to use the rifle to patrol or defend, though.
Planning to use your AR-15 for home defense? In this case, you’ll want a carbine gas system and barrel length as the standard rifle variants are better used for long-range shooting and won’t serve you as well up close.
Some uppers are more compatible than others, so always check before you purchase that the component you opt for is suitable to use with any other AR-15 parts you’ve already purchased, to avoid disappointment.
There are four different kinds of AR-15 uppers in manufacture, which are typically distinguished by the presence or lack of a fixed carrying handle:
AR-15 A1 - the traditional upper for such rifles, designed in the 1960s for use in the Vietnam war; there’s a light profile barrel, forward assist, triangular handguard and a fixed carry handle. Replicas of this design remain highly popular purchases today.
AR-15 A2 - a slightly upgraded version of the original, developed in the 1980s, improvements include an adjustable rear sight (for windage and elevation), heavier barrel and round handguards, maintaining the fixed carry handle and forward assist.
AR-15 A3 - the first design to include a detachable carrying handle, this model varies depending on the manufacturer, sometimes utilizing Weaver or Picatinny rails for mounting sites and scopes, and keeping the old-school forward assist.
AR-15 A4 - another flat-topped model, not unlike its predecessor the A3 in design, this update tends to feature M4-style feeding ramps, for a much more efficient cartridge loading experience, and is the most commonly used design nowadays.
Frequently Asked Questions
Is the upper or lower more important on an AR-15?
Provided that both parts have been forged well, they’re essentially the same in terms of importance, though your upper is more likely to affect the reliability and accuracy of your firearm than the lower is.
In terms of the law itself, the lower of a firearm is what’s considered to be the firearm itself, which means they are more difficult to buy and therefore more thoroughly regulated with greater restrictions on their purchase.
Can you mix and match AR 15 uppers and lowers?
Whilst some critics would suggest that using components from different brands instead of a matching pair will impact upon the quality of your weapon, it’s just not true - as long as both are of a high standard, there’s no reason for issues.
Just make sure that the upper you’ve gone for explicitly states it is compatible with the lower of your choosing. Most manufacturers will clearly declare this, but you could also check the reviews for advice from other customers.
Are polymer AR uppers any good?
Though they might be more affordable, uppers made from polymer are far less likely to withstand damage and protect you from the power of letting off a shot. Stump up the extra cash and go for a sturdier choice.
As you can see, all of the uppers we’ve selected are made from carbon steel or aluminum, and have been forged and machined to adhere to military specifications, which makes them not only more dependable, but likely to last for years longer.