If you’re looking for an 80 lower for your next build then you’ve come to the right place. We specialize in everything AR-15 and, specifically, 80% lower receivers, lower parts kits, and lower assemblies. If you’ve never built an AR-15 using an 80% lower…no worries. We’ve all been there. Don’t be intimidated by the process but make sure you build with quality lower receivers like ours.
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Showing all 12 results
An 80% lower is a lower receiver that requires additional milling to turn it into a functional receiver. It is, essentially, a piece of aluminum that is partially completed during the forging process. It requires special tooling as well as the know how and patience to complete the lower and be considered a firearm. The ATF does not require the use of a FFL (Federal Firearms Licensed) to transfer ownership of an 80 lower receiver.
In order to mill your 80% lower, you’ll need a number of tools including an 80% lower jig, router, various bits, and quality handheld or table-top drill press. Yes, it requires a good amount of work and will definitely take up a Saturday but there is nothing like shooting an AR-15 that you built.
While forged 80% lower receivers are usually more popular, there are a number of choices available in both the type of lower and the style of the lower. Choices range based on material used, size of the lower, as well as the coating or finish of the lower done at the forging house.
There are typically two different types of material - aluminum and polymer. Aluminum options are broken down further by the type of aluminum used based on the machining method.
Cast lowers are typically considered the weakest of lowers due to the method of manufacturing. Casting an 80 lower is done by pouring molten aluminum in a cast and the finishing with a sander. Cast lowers have less density and, therefore, are inherently weaker.
Forged 80 lowers are made from compressed blocks of aluminum, typically 7075 grade. The block of aluminum in inserted into a press equipped with a mold and then pressed, or forged, into its shape. The lower is then machined finished.
A billet lower differs in that it is entirely machined into its shape from a solid block of aluminum, also known as bar stock. The bar stock is inserted into a CNC machine which then cuts the aluminum into a raw 80 percent lower receiver.
The last material, and likely the most controversial, is polymer. Polymer is essentially hardened plastic and 80 lowers are machined into shape similar to billet. The main difference, as you can guess, is that the hardness and durability of polymer is drastically different than forged and billet lowers. Builders that are knowledgable of polymer 80 lower receivers are typically either advocates or critics.
While there is debate around the hardness and durability of forged lowers versus billet lowers, forged is typically harder and more durable while billet and polymer lowers provide a better aesthetic finish.
While the material used in an 80 percent lower varies, the finish applied (or not applied) to the lower can vary even more. The standard and most popular finish for aluminum lower is black anodization. Using an electrochemical process, the finish is applied to not only for aesthetics but also to increase durability and corrosion-resistance. Other colors can be applied during or shortly after anodization and typically depend on the aluminum used.
Another popular option is buying raw 80 percents. This is a forged or billet lower that has no coating and, instead, will need to be coated after milling. The reason to purchase raw lowers is so that an even finish can be applied to the entire milled lower. This means the fire control pocket would also have the finish applied to it.
For polymer 80 lower receivers, the color choices available are vast. Unlike aluminum, the polymer is dyed to the desired color before machining. If color is an important factor, polymer receivers may be a suitable choice.
On a national basis, the ownership of an 80 lower receiver is completely legal and unregulated. Once the 80 percent lower is milled, however, it's important to remember that national regulations under the National Firearms Act, or NFA, will apply. While a serial number is not required, it's still a good idea to engrave a serial number of your choosing, a model number, and even the manufacturer.
The biggest caveat to building your own rifle from an 80 lower is based on the state you reside in. Some states, counties, and cities regulate and even prohibit the building or manufacturing of a firearm for personal use. It's important that you seek out the legality of building your own AR-15 in your home state, county, and city.
When it comes to finishing your 80 percent lower, you'll need to make sure you have the proper tools as well as a method that accommodates the tools you have. There are a number of ways that the lower receiver can be milled and finished including the use of a drill press, a router, and/or even a hand drill. More extreme finishing methods include the use of CNC machines. For most builders, a drill press or router is sufficient and readily accessible.
Aside from a drill press, router, drill, or CNC machine, you'll need the proper jig and tooling bits. 80 percent lower jigs can vary widely with some being much easier to use than others. In most cases, though, they all contain the same components including the side plates and two variations of top plates. The top plates will have areas for milling the fire control pocket as well as the pocket shelf.
The size of the drill bits will be largely based on the jig used but typically four to five different bits will be needed. The most important, and often hardest to find, is the end mill bit. The end mill bit is what is used to finish the fire control and shelf pockets and, therefore, give you a smooth, professional look and feel.