What is a Stripped Lower Receiver?

In order to understand what a stripped lower receiver is, we must understand what a regular lower receiver is and does. Simply put, the lower receiver is the frame that houses a few crucial firearm components: the trigger assembly, safety controls, magazine well, buffer tube, stock, and grip.

Without the lower receiver, there is no mechanism for firing the gun. Thus, for AR-15’s, the lower receiver is considered the actual firearm, thereby requiring a serial number (more on that later) and an FFL dealer to transfer the weapon.

WHAT IS A STRIPPED LOWER RECEIVER?

So, what are stripped lower receivers? It is a lower receiver without any of the internal components, i.e. it’s the block of metal/polymer without the trigger, safety, magazine, etc.

WHY BUY STRIPPED LOWER RECEIVERS?

Despite not coming with a trigger or magazine, stripped lower receivers are still considered a firearm, have serial numbers, and must be purchased or transferred through an FFL dealer.

The reason builders choose stripped lowers is that it allows them to customize the build according to their preferences and intended use. For example, perhaps they’re building a competition AR-15 and want a particular trigger for it. Or they have a preference on which stock and buffer to use to absorb recoil.

Stripped lowers offer the ability to pick and choose the specific trigger, grip, or other internal lower parts that are desired.

You can imagine experienced shooters that know what they want and like will find stripped lower receivers very appealing because of the flexibility it offers when building a new rifle.

COMPLETE LOWER RECEIVERS

Unlike stripped lower receivers, complete lowers will come pre-assembled with a trigger, safety, and magazine assembly. Often, they include a stock and buffer tube already installed as well. Basically, there is no assembly required, other than pinning it to the upper receiver.

Because of this, a complete lower receiver is also considered a firearm and requires a background check prior to purchasing. Most complete lowers are pretty basic and will lack many of the higher end upgrades builders like to incorporate such as an improved trigger or grip.

80% LOWER RECEIVERS

What if I told you there’s a lower receiver you can buy that doesn’t require a serial number or an FFL transfer? Sounds good, right?

There’s a middle ground where the ATF considers the lower to still be considered raw materials and not a finished product, thereby not requiring a serial number. That middle ground is 80%.

If the block of aluminum is only 80% finished, it is still not considered a finished product.

The companies that forge lowers can mill and drill them, but leave the final 20% of the work to be done to the buyer. Because you have finished it yourself, the ATF considers your efforts to be that of a gunsmith, and therefore, the lower does not have to be serialized.

Before you get too excited, just know that some 2A-restricting states have different laws as it pertains to 80% lowers and still require a serial number. Do your own research on your state’s specific laws before making a purchase. If your state does not restrict 80% lowers, you can have it delivered to your front door. No need for an FFL!

Another important note, finishing a lower does require some skill in milling and assembly is required. You will need access to a drill press and precision jig, whereas stripped uppers are ready-to-go out of the box. There are plenty of tools and videos out there to help you on your journey if you decide to go the 80% route.

You will not be able to install the lower parts kit (LPK) until this work is completed.

All that being said, you can see how this would appeal to some operators that prefer to stay off the ATF’s radar. But if you prefer to not mess around with all of the work involved, and don’t care that the lower has a serial number, then you want to stick with a stripped lower receiver when building.

HOW DO YOU TRANSFER A STRIPPED LOWER RECEIVER?

It’s a fairly simple process. Once you find the lower of your choice, you will need to have the receiver shipped to a licensed FFL dealer just like you would for any other firearm. Most retail websites will ask you what FFL you would like this shipped to during the checkout process. The FFL will charge a fee for processing the transfer, usually between $50-$75.

One difference with transferring a stripped lower is that since the firearm is not completed yet (it could be made into a rifle or SBR) the paperwork filled out by the FFL will likely mark the receiver as “other” under the type of weapon question.

In short, ship the receiver to the FFL, they will fill out the paperwork, and the lower receiver will be transferred to you.

WHERE TO BUY A STRIPPED LOWER RECEIVER

There’s a number of great retailers that offer stripped lower receivers, but it all depends on what your needs are. That’s why we put together a list of the best AR-15 stripped lower receivers. Check it out, as we have recommendations on where to pick up each lower.

Justin Trump

Justin Trump is the managing editor and owner of CAT Outdoors. The son of a Vietnam veteran, he’s an avid gun enthusiast and 2A advocate. He holds two firearm patents for the CAT M4 and Talon tools. When not managing CAT Outdoors, he enjoys spending time with his family and friends, rooting for Michigan sports teams, and serving his church.