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Choosing an AR 15 Upper

Choosing an AR 15 Upper

June 30, 2017


If you’re new to the AR 15 community, there can be a lot of potentially confusing terminology thrown around. Those who own other firearms have a bit of a leg up, but only somewhat. However, as overwhelming as it is, it’s important to take the time to familiarize yourself with the terminology, as well as all the different components to the AR so you can fully enjoy the benefits of this particular firearm. As we’ve discussed once or twice before, part of what makes the AR 15 such a great option, as far as firearms go, is because of how easily customizable it is. However, before you dive into customizing your AR, you need to know what all those components are and how they work together. For those of you who are new to the AR community, here are a few things to keep in mind when it comes to choosing your upper receiver or swapping out components.

Know Your Uppers

First and foremost, in case you missed it, here’s a very important clarification: the lower receiver is the only part of the AR that is technically the firearm. This means only the lower receiver needs to be serialized, registered, and bought through a dealer. Because of this, all the components of the upper receiver can be bought from any seller, even online. This is what has allowed so many manufacturers and designers to create custom AR parts and accessories. So breathe easy when you go online to shop for that new rifle handguard or barrel length; you aren’t doing anything illegal. However, be sure you’re checking state laws, as there are a couple accessories or components that may not be allowed in your state.

When it comes to the AR 15 upper receiver, basically every part can be swapped out for a different option. The biggest concern there is ensuring you’re exchanging components made to chamber the same caliber rounds. That being said, here are some of the options you can choose between when it comes to uppers.

Flat Top or Carry Handle

The standard options for an upper receiver are either flat top, which means it comes with a flat Picatinny rail on top, or a carry handle top, which should be pretty self-explanatory based on the designation. A1, A2, A3, and A4 are all terms you’ll hear tossed around, and these denote the generation of the rifle when talking about the M16, the U.S. Military’s version of the AR 15. Essentially, the biggest easily discernable difference is whether the version is flat topped or has a carry handle. There are more differences between the four, but those aren’t important right now. When choosing an upper, you’ll first need to decide whether you want a rifle with a carry handle or a rail on which you can attach accessories.

Construction and Material

The next big question is whether you want your upper to be forged, billet, or cast. A forged upper is, as you probably expect, one that is forged, or hammered, into the proper shape and finished with a CNC lathe. These are generally heavier and denser, but makes up for the added weight in hardness and fatigue limit. A billet upper is one that is made using a CNC machine to mill a solid chunk of metal into the proper shape. These are usually not quite as heavy as a forged upper, but they are also a bit less durable than their forged counterparts. Finally, cast receivers are those that are made using molten metal shaped by a mold—this process may also be referred to as “die casting.” Cast uppers will usually be the lightest option, but because of how they are made, they are generally the least durable option.



How DIY Do You Want to Go?

When purchasing an upper receiver, you’ll see a few different categories of options beyond those we’ve already mentioned. A stripped upper is exactly what it sounds like; it will be just the receiver, no extra components. A complete upper, on the other hand, may be one of two different options. A complete upper will generally be an upper receiver with the ejection port door and forward assist button installed. A “complete upper assembly,” however, will be those three components with the addition of the barrel, handguard, charging handle, and occasionally even the bolt carrier group.

Once you have your upper assembly picked out, purchased, and put together, it’s time to get everything kitted out the way you want. Rail mount accessories like a rifle handguard with rail scales or a vertical grip can help you keep a firmer grip and help you with your accuracy when shooting—assuming you take the time to practice, practice, practice. For lightweight, low profile,  and heat-resistant rifle handguard accessories, shop Rail Scales online today!