Best Budget Pick: Aero Precision Stripped Upper Receiver
The Aero Precision is a good choice if you are looking for a stripped upper receiver that you can customize yourself by selecting and then installing yourself. While the takedown holes are a bit tight, it’s still out of high grade aluminum and is compatible with most mil-spec 5.56 AR-15 lowers.
Best High End Pick: Wilson Combat AR-15 Billet Upper Receiver
The Wilson Combat AR-15 Billet Upper Receiver is built for precision use to ensure maximum accuracy potential. Built out of aircraft grade 7075-T6 aluminum and coated in an anodized finish, this upper receiver was designed by WC from the ground up to address perceived weaknesses in the structural design of an AR-15. It also comes equipped with a precise bolt raceway, a shell deflector, and M4 style feed ramps to ensure solid reliability.
Best Value Pick: WMD Guns AR-15/M16 NiB-X Coated Upper Receiver
The WMD is built out of aircraft grade aluminum and comes coated in a NiB-X finish that is more durable than chrome plating and has been designed to withstand 30,000 rounds. If you want an upper receiver that you know can last you for a long time and that won’t break your bank, this is a solid choice to go with.
Best Overall Pick: Sharps Bros Assembled AR-15 Upper Receiver
The Sharps Bros Assembled AR-15 Upper Receiver is a complete upper that comes ready to install on your M16A1. Built out of 7075 aluminum, coated in a mil-spec grade anodized finish, and compatible with multiple different calibers, this receiver is ready to go right out of the box.
The most popular centerfire rifle in the United States today is the AR-15, and it has been for several years. But do you want to know where the AR-15 originally began?
It originally began with the M16A1 rifle. The AR-15 platform as we know it today, with all of its different variants and spare parts and accessories available on the market, can be linked back to the M16A1 from the late 1950s.
If you want to build together your own personal M16A1, the two most important components you will need are the lower receiver and the upper receiver. We’ll talk about the latter today.
In this guide, we’ll dive into a history and overview of the M16A1 rifle, the purpose behind the upper receiver and the top qualities to look for in one, and then our choices for the top three best upper receivers for an M16A1 in today’s market.
An Overview of the M16A1 Rifle
The AR-15 as we know it today can be traced all the way back to the M16A1 from the late 1950s.
The standard issue rifle for the United States military during World War II was the M1 Garand rifle, which was an excellent rifle that was more technologically advanced to the bolt action services rifles of other nations during the war. However, by the 1950s the M1 was also showing its age as rifles with detachable box magazines such as the AK-47, FN FAL, and HK G3 began to equip the world’s other militaries.
The US military reacted by modifying the M1 Garand to shoot the .308 Winchester round, adding a detachable box magazine, and shortening the gas tube. The result was the M14 rifle, or the M1A as its own in its semi-automatic only configuration for civilians.
While the M14 was a fine rifle that was arguably a solid improvement over the M1 Garand, it also had its faults. Most notably, it was simply too big and heavy, and the hefty .308 round it fired was simply too big and heavy for jungle warfare in Vietnam.
What the military needed was a smaller and lighter rifle that was more maneuverable and that fired an intermediate cartridge so a soldier could carry more ammunition for less weight. The result was the M16A1, or the first major iteration of the AR-15 rifle (which in turn had been developed from the AR-10). When the AR platform was originally designed by Eugene Stoner, little did he know that it would eventually become one of the most successful rifles of all time. Today, after all, the AR-15 is the bestselling rifle sold in the United States and is in service with countless militaries, law enforcement units, and special forces all over the globe.
The M16A1 is notably different visually from other M16 rifles for its triangular hand guard, stock that lacks a compartment, and 20 inch barrel and rifle length gas system. It originally lacked a forward assist and came equipped with a three pronged flash suppressor, along with a parkerized finishing that was very resistant to rust and corrosion. Parkerizing came standard as a finish on most American military weapons, including the M1 Garand and the Colt M1911A1 pistol, for this very reason.
The M16A1 was later developed into the XM16E1, which added a forward assist and notches in the bolt carrier and was produced from 1967 to 1982. Several other improvements were made to the M16A1 as well. For instance, the three pronged flash hider originally present on it caught on twigs often, so the XM16E1 added an improved hider that mitigated this issue.
The M16A1 eventually paved the way for more M16 generations (such as the M16A2 and the current M16A4) and its shorter cousin the 16-inch barreled or shorter M4 carbine (the 16 inch version is the most common AR configuration with American civilians today). While no longer in service with the American military, the M16A1 is still used by numerous other militaries around the world, as the US government sold much of its existing M16A1 stockpile to other governments when new versions of the rifle were developed.
In essence, it really was the M16A1 that started it all when it came to the AR-15 platform. This is also why the M16A1 has seen a resurgence in the American market over the last few years, as companies such as Brownells have sought to release their own versions of the M16A1 to appeal to buyers who are interested in a rifle with a much more classic look.
If you’re looking to put together your own M16A1, one of the most important components that you will need to consider is the upper receiver. Simply put, without a quality upper receiver, you won’t have a quality rifle. In the next sections, we’ll talk about why you should upgrade your upper receiver, and then we’ll discuss the top features to look for in one.
Why Should You Upgrade Your Upper Receiver?
The upper receiver is simply the upper part of the AR-15. It includes the metal housing, barrel, hand guard, ejection port, forward assist, rail system, bolt carrier group, and so on.
When you combine a complete upper receiver of an AR-15 with a complete lower receiver, you create a fully functional rifle that is ready to go. And while both components are vitally important, the upper receiver is arguably the most important because it’s the part that impacts the shooting performance of your rifle the most.
That’s why while there are many reasons to consider upgrading your upper receiver, but the biggest reason first and foremost is to improve the performance of your rifle.
For example, when you build a rifle with higher quality upper components, you can potentially boost the rifle’s performance by up to 50%.Furthermore, building your M16A1 with higher grade components such as aircraft grade 7075 aluminum will greatly help to improve its durability as well.
Buyer’s Guide For The Best M16A1 Upper Receivers
These are the most important factors to consider when looking for a new upper receiver for your M16A1:
Complete vs. Stripped
When choosing any upper receiver, you will always need to choose between going with a stripped upper or a complete upper. It shouldn’t be hard to choose which one you should go with depending upon your intentions for the rifle.
A stripped upper receiver is any upper receiver that is not complete, meaning that there are additional components that you will need to acquire and install yourself on the rifle. The specific components that you need to get will vary depending the upper that you are considering, and it’s your responsibility to make sure that you find out which specific parts that you need to get.
A complete upper, on the other hand, comes with all of the parts already installed so it’s immediately ready to merge with a lower receiver (assuming that the lower is complete as well) in order to form a complete rifle. Since a complete upper receiver comes with everything installed already, it will be more money out of the box, but keep in mind you’ll also need to spend the cash on the components you need in order to transform it into a complete upper.
In short, you should go with a compete upper if you don’t want to deal with any hassle or parts fitting, but you should go with a stripped upper if you want to customize your rifle to make it truly your own.
Your upper receiver should come with a rail over the top in order to make it easy to add lights, lasers, scopes, red dot sights, or other accessories. The best kind of rail to get will be the M1913 style Picatinny rail, as it will be compatible with the highest number of spare parts and components.
Forward Assist and Dust Cover
A dust cover is designed to keep grime out of the ejection port when the rifle is not in use, while the forward assist can help clear a jam in the event the round does not go all the way home. While neither the forward assist or the dust cover is truly necessary in order to ensure proper function, both pieces are good to have, and ideally your upper receiver will come with them.
In the event that you go with a stripped upper that does not come with these components, you make sure that it at least gives you the option to add them.
The best upper receivers are built out of aircraft grade 7075-T6 aluminum, which is both lightweight and highly durable. It’s a far better choice than either polymer or 6061 aluminum, both of which are durable in their own right but not as much as 7075 aluminum.
Also make sure that your upper comes with a durable rust and wear resistant finish as well, such as nitride or an anodized finish. This will ensure that your upper will hold up better in rough conditions or inclement weather.
The 4 Best M16A1 Upper Receivers For 2020
Now that we’ve covered why you need to upgrade your upper receiver and the top qualities to look for in one, here are our choices for the top four best M16A1 upper receivers for 2020:
WMD Guns AR-15/M16 NiB-X Coated Upper Receiver
WMD Guns is a company that is known for their high quality finishes and coatings on firearms. This upper is no exception, coming with a NiB-X coating that is more durable than chrome plating and is designed to easily withstand 30,000 rounds. Specifically, the NiB-X includes nickel boron with a durability greater than Melonite or Tennifer as well.
The body of this receiver is built out of aircraft grade 7075-T6 aluminum, and is available in a black, nickel, OD green, or flat dark earth color pattern. The extended M4 feed ramps ensure reliable feeding, but the takedown holes are also very tight and may require further fitting from a gunsmith.
The WMD Guns NiB-X Coated Upper Receiver comes coated with a finish that is more durable than Chrome plating while also being built out of aircraft grade aluminum. If you want an upper for your M16A1 that you know is built to last, this is a solid option.
- More durable than Chrome plating
- Built out of 7075-T6 aluminum
- Comes with extended M4 feed ramps
- Since it’s a stripped receiver, you’ll need to add additional parts yourself or with the aid of a gunsmith
Aero Precision Stripped Upper Receiver
Available for an affordable price point, this Aero Precision is a stripped upper receiver that is compatible with most mil-spec grade AR-15 lowers. It comes with quality M4 feed ramps to ensure consistent reliability and is built out of high quality aircraft grade 7075 aluminum with a hard coast class 2 anodized finish for good resistance against rust and wear and tear. In addition to black, you can also get the Aero Precision in cerakote FDE or cerakote OD green.
While this is designed to be compatible with most mil-spec AR lower, the drilling holes may be a bit tight depending on the lower you’re going to match it with, and this may require the aid of a gunsmith. But if you’re looking for a solidly built M16A1 upper at a good price point.
Overall, the Aero Precision Stripped Upper Receiver is a solid choice if you are looking for a stripped upper receiver that is ready for you to customize. Aero Precision designed this upper receiver to be compatible with most mil-spec 5.56 lowers, which means it will be a fine option for your M16A1 built. Just take note that the takedown holes are bit tight and may require more fitting from you or a gunsmith.
- Features M4 Feed Ramps
- Built out of durable 7075-T6 aluminum
- Compatible with most mil-spec AR-15 lowers
- Comes with M4 feed ramps
- Takedown holes are a bit tight
- You’ll need to buy extra components yourself
Sharps Bros Assembled AR-15 Upper Receiver
The Sharps Bros Assembled AR-15 Upper Receiver is a complete upper receiver that come ready to install right out the box. It’s compatible with multiple different AR-15 calibers, including .224 Valkyrie, 6.5 Grendel, .300 Blackout, .223 Remington, and 5.56x45mm NATO receiver. However, due to the size of the ejection port, it cannot accommodate rounds such as .458 SOCOM or .450 Bushmaster.
This upper is built out of 7075 aluminum and is coated in a mil-spec anodized finish, so it’s very durable and rusts resistant. It also comes equipped with a forward assist and a dust cover. All you’ll need to do is add your handguard and a barrel, and it’s ready to go.
All in all, the Sharps Bros. is a solid choice for a complete upper receiver for your M16A1. Compatible with multiple different cartridges and built out of high grade materials, this is the kind of receiver that you can use forever and pass on down to the next generations.
- Compatible with multiple different AR-15 cartridges
- Comes complete and ready to install right out of the box
- Built out of 7075-T6 aluminum
- Coated in a mil-spec anodized finish
- Can’t be easily customized since it’s already assembled
Wilson Combat AR-15 Billet Upper Receiver
The Wilson Combat AR-15 Billet Upper Receiver was built by WC for precision use, in order to ensure maximum accuracy potential. Wilson Combat also built this upper receiver from the ground up to address perceived structural design weaknesses from a structural Wilson Combat receiver. WC argues that this approach helps to both improve durability and tolerances.
Wilson Combat built this upper receiver from aircraft grade 7075 aluminum along with a coating of mil-spec grade black anodized finishing to ensure solid rust and corrosion resistance. It also comes equipped with M4-style feed ramps to ensure good reliability, an undersized bolt raceway to improve feeding and chambering, a Picatinny rail so you can add sights and optics. and a shell deflector.
The one negative about this receiver, besides its expense, is that it will not accept all aftermarket bolt releases, so to stay on the safe side you should invest in Wilson Combat bolt releases instead.
Overall, the Wilson Combat AR-15 Billet Upper Receiver is a solid upper receiver for an M16A1. Built out of 7075 aluminum and designed for precision use to maximize accuracy potential, this is an upper that can last for a lifetime.
- Built for precision use for maximum accuracy potential
- Comes coated in a mil-spec grade anodized finish
- Built out of aircraft grade 7075-T6 aluminum
- Has a Picatinny top rail to add sights and accessories
- M4-style feed ramps ensure good reliability
- Very expensive
- Is not compatible with all aftermarket bolt releases
And that concludes our list of the top four best upper receivers for an M16A1 for 2020. Today there are simply more parts available for an AR-15 in general than there ever have been before. While this means that you have a plethora of different options for accessories, it also means it can more difficult to choose one, and the upper receiver is no exception.
Fortunately, any one of the four upper receivers that we have covered here today will be an excellent option for your M16A1 build. Also remember that you can always refer back to our buyer’s guide at any time when searching for a new upper receiver as well.
Featured image by u/DaddyDano