What is an AR Upper?

While it may seem confusing, guns are quite simple as long as you get good answers. I’ve had questions myself that no one cared enough to answer.

An AR upper is the top half of the frame of an AR-style firearm. It attaches to the rear of the barrel and houses the bolt handle and bolt carrier group. Uppers can be stripped, barreled, or completed. A completed upper can be installed on top of a lower receiver and the gun will fire. An upper does not require a background check.

There’s a lot of different types and styles of uppers. Some come ready to go, some require assembly and special tools, and some just need a simple part to work. Don’t worry, I’ll explain it all to you. Feel free to ask any questions in the comments

What an AR Upper Does

An AR upper houses the mechanism that cycles ammo in and out of the gun, and locks it in place in the barrel for firing. It’s also what the barrel and handguard mount to. With standard configuration AR-rifles, it also houses the bolt handle, which serves as a cocking mechanism, and the forward assist which lets you force close the bolt.

The upper serves as the piece that brings everything together. the barrel, handguard, and sights or optics are mounted on the upper. The upper, once completed, is installed on top of a finished lower to complete the assembly of an AR-style rifle, more properly called a Modern Sporting Rifle, or MSR.

I don’t like to say, AR-15, because the genuine AR-15 rifle is actually an antique that hasn’t been made since 1964. The modern rifles are a continuation and progression of that style of design but are not AR-15s. The AR-15 was mainly a Prototype from 59 to 64 before it was sold and modified into the M16 for the US Airforce in 1964. Now you know.

There is nothing dangerous about an upper. It’s just a hunk of aluminum. For folks who want to assemble their own Modern Sporting Rifle, assembly of the upper is the only part that requires any specialized tools. You will want a Barrel Wrench and an Upper Vise Block (to be used with a bench vise), to put the gun together.

There is nothing complicated about an upper or about assembling one. These guns are pretty simple in design, which is part of why they got so popular. That, and they’re just easy to use.

What is Included in an AR Upper?

Uppers come in three main levels of assembly. There are stripped uppers which are only a shell and have no extra parts, barreled uppers, which have a barrel and handguard, but no internal parts, and complete uppers which are ready for function, but may need sights.

Here is a side charging upper, completed with the Bolt Carrier Group.

The upper itself is just a well-machined piece of aluminum. Although, there are some specialty models made of stainless steel or titanium. They come coated in an anti-corrosion material that comes in a variety of colors.

Different Types of AR Uppers

There are two main styles of upper receiver; the “Flat-Top” and the “Carry Handle”, also called “High-Top”. Flat-Top uppers have an accessory rail on top to mount a sight or a scope. Carry Handle uppers have handle-like riser on top that serves as a durable rear sight. Flat-top uppers are more popular and offer more user customization and utility.

All uppers fall into one of these two categories. The original design from the 1950s did not take into account a way to use a scope, so the High-Top upper became the first design. It was designed with a raised rear sight to alter the trajectory path to allow 300-yard battlefield use.

For most shooters today, that does not apply well. We tend to be more with precision and customization. The flat-top upper offers the option of using any type of sighting or aiming device. The High-Top upper can’t do that. However, you can get a rear sight for a Flat-Top that looks like the older style.

The High-Top is usually called a carry handle style. It looks like it has a nice handle on the top of the upper and people started using it for that in the Vietnam War. But it’s really just a design for a high, durable sight. It’s not made to be used as a handle. Don’t do that, it can mess up the sight.

Within those two types of uppers, there are two other main versions; the rear-charging and the side-charging. Charging a gun means preparing it to fire. Rear-charging is the standard. They have a T-handle in the back that you pull after a loaded magazine is inserted.

Pulling and releasing the handle grabs a bullet from the magazine, and thrusts it into the chamber. The bolt then locks in place so the cartridge can safely fire when you are ready. The gun is then charged. Side-charging uppers have a short handle on one side, which is pulled back and released for the same function.

Side charging uppers are not of military design. They are more like a traditional Semi-Auto hunting rifle. Traditionally, we use our firing hand to charge a rifle, which is why they made side charging MSRs. The rear-charging upper was made to work with right and left-handed shooters, and to let you keep your firing hand on the weapon.

You can see the upper with the rail and scope on top, and how it sits onto the lower half with the trigger.

Where to get an Upper?

Palmetto State Armory and Bear Creek Arsenal are the most popular places to buy completed or stripped uppers. Uppers can be bought online and at most gun stores. Because they don’t require a background check, you can order one and have it shipped to your door.

Uppers don’t require a background check because the ATF does not consider it a firearm. It’s legally and functionally the same as buying a gun barrel. There are no federal restrictions and they can be bought or sold without question.

The lower receiver is, however, and can only be sold through a dealer unless the transaction is done without crossing state lines and is sold by a private individual.

Personally, my favorite place to get a fully functional upper is Bear Creek Armoury. They are cheap and definitely don’t look fancy, but they tend to work well. I have bought 5 of them myself and am considering a promotional deal with them in the future. I really like their side-charging uppers. If you want something a bit nicer, check our AERO Precision.

How much do Uppers Cost?

A stripped upper receiver costs between $30 and $250. The normal amount paid is around $60. Completed uppers cost between $250 and $1,000. You can get a reliable complete upper for under $350.

Anther great article you might be interested in is Best AR Calibers for Home Defense

Jordan Buck

Jordan Buck is an outdoor writer, a man of faith, and a family man. He grew up hunting, fishing, and trapping. Jordan has taught marksmanship, woodsmanship, and self-defense classes. He has earned black belts in four martial arts and is a certified Krav Maga instructor. He also runs his own Gun Blog and YouTube Channel. Jordan enjoys giving his time and resources to help others and has spent 15 years volunteering in a boy's mentoring program He is and will always be an American Patriot. MOLON LABE

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