AR-15 lowers have quite lately been an object of interest among firearm enthusiasts. Complete, stripped and 80% receivers differ in price and ease of installation and have their respective characteristics. Here we’ll be talking about complete AR-15 lower receivers, their features and how they are made.
We’ll also be discussing the factors to look for when choosing an AR-15 complete lower. To help you make a buying decision, we have also reviewed some the best AR-15 complete lowers available in the market.
Comparison Chart of the Best AR-15 Complete Lower Receivers
Bravo Company AR-15 Complete Lower Receiver with BCM Gunfighter Stock
Spikes Tactical AR-15 Complete
Colt AR-15 Complete M4 Lower Receiver
Yankee Hill Machine Co. Inc.
Spikes Tactical AR-15 Complete M4 Lower Receiver
What is a Complete Lower Receiver?
As the name suggests, a complete AR-15 lower receiver is like a plug-and-play product. You unwind the package, fit in a couple of pins to join it to the upper receiver, and you’re done. Your AR-15 is ready to fire.
A complete lower receiver houses the entire fire control group. In detailed terms, a complete AR-15 lower includes:
- Trigger Assembly
- Bolt Catch Assembly
- Trigger Guard
- Hammer Assembly
- Magazine Catch
- Selector and Safety Switch Assembly
- Buffer Tube Assembly
Complete AR-15 Lower Receivers are generally billet-machined or forged from metal, usually aluminum. All the holes, magwell, threads and other features are precisely engraved and machined onto the receiver so it fits the upper and other parts perfectly.
According to the US Law, a complete or stripped receiver is considered to be the firearm itself. This means that the sale, purchase and possession of a complete AR-15 lower receiver are regulated by federal laws as well as applicable laws in your state.
Each complete lower receiver must bear a serial number. To purchase a complete AR-15 receiver online, you must have it shipped to a dealer with a valid Federal Firearms License. Additionally, you must undergo a background check and present your valid ID to buy one online or through a dealer.
It is important to always be aware of the laws that are in effect on the federal, state and local levels that govern the transfer of firearms. Those laws apply to the receiver, or in the case of the AR-15, to the lower receiver.
Factors to Look For
Before choosing a complete lower receiver for your AR-15, there are several factors you must consider.
AR-15 lower receivers are generally manufactured from aluminum or polymer. Basically two different types of aluminum (6061-T6 and 7075-T6) can be used to machine or forge these receivers.
The 6061-T6 aluminum is generally used in the manufacturing industry for everything from vehicles to utensils and firearms. It has superior workability characteristics and hence the use.
The 7075-T6 aluminum on the other hand is aircraft-grade aluminum which makes it more durable and tough as compared to 6061-T6 aluminum.
Polymer lower receivers on the other hand are lightweight but not so durable in the long run. Plus they are more susceptible to damage and wear ‘n tear.
Type: Billet or Forged
Forged is the traditional style of manufacturing receivers where the metal is melted and shaped using hydraulic hammers. It’s simple, effective and it’s the method the U.S. military chooses for their M16/M4 lower receivers.
On the other hand billet receivers are machined and hence bear cleaner lines and are heavy duty. Plus they have a unique and cleaner look. Receivers made from polymers are generally injection molded, but type is not much of a concern with polymer lower receivers.
Finish: Hardcoat anodized, Cerakoat, or None
If you choose to buy an aluminum complete lower receiver, you must consider its finish. Aluminum for firearms is generally hardcoat anodized (type III) which is similar to standard anodizing (type II) but provides a superior and more resistant coating to the metal.
Additionally, hardcoat anodizing is also the preferred military standard. Apart from this, you can also opt for a cerakoat or duracoat finish to impart durability and longevity to your complete lower receiver. It is generally not recommended to buy lower receivers with no coating and the reason is pretty obvious.
Hardcoat anodized receivers generally come in black whereas duracoat- and cerakote-finished lower receivers are available in a wide range of colors.
Manufacturer and Quality Control: Precise holes, roll pin holes, magwell
Before choosing a lower receiver for your AR-15, you must consider the trust and reliability associated with the manufacturer. Quality control is an important aspect while purchasing a lower receiver.
You need to make sure that all the holes are placed precisely and are perfect in shape. The magwell has to be aligned properly and is perfect in size. Plus all the components such as the trigger, safety and selector switch must work properly.
Choosing a lower receiver from a renowned manufacturer eliminates the possibility of getting a defective product. Additionally, renowned manufacturers generally offer a limited or lifetime warranty or guarantee so you always have your back covered.
Last but not the least, you want your rifle to look cool. So you must take note of the aesthetics of the complete lower receiver you are going to buy. From logo and color to any other engravings on your complete lower receiver, you should consider browsing around to find the design you like.
Quick Take - The Best AR-15 Complete Lower Receivers
These are our recommendations for the best complete lower receivers for the AR-15:
Review of the Best AR-15 Complete Lower Receivers
Here we have outlined some of the best AR-15 complete lowers available in the market. Keep reading below for more in depth reviews of each lower receiver.
The Bravo Company AR-15 Complete Lower Receiver is forged from 7075-T6 aircraft grade aluminum and is hardcoat anodized. Bravo Company is a renowned manufacturer and all the parts in this complete lower receiver are trademarked BCM components.
The receiver is multi-caliber and can be used for customizing the rifle later. The fire controls are marked as ‘safe’ and ‘semi’ and the receiver features a BCM Fighter gun stock.
The fit and finish of this lower receiver are second to none. The receiver features an unnotched hammer which makes it compatible with 9mm use.
BCM’s customer service is second to none so this will be another positive of purchasing this complete lower receiver.
Some people may fret upon the price, but it's actually in line with its counterparts.
The Spikes Tactical complete lower has been machined from 7075-T6 aluminum, which ensures the quality, durability and corrosion resistance of this product. The lower has been hardcoat anodized and features stamped and color-coded selector position markings. That’s a tactical plus.
The receiver can operate in ‘safe’ and ‘semi-auto’ modes and also possesses a fake non-selectable ‘full auto’ position, just for that swag. It also features a six-position mil-spec buffer tube and an M4-style buttstock molded from reinforced polymer to help reduce the weight.
This complete AR-15 lower receiver offers good value for money, works with many guns and is tough. The price is relatively cheap, but that doesn’t compromise its quality.
Manufactured by one of the most popularly known firearms manufacturers, this complete lower receiver offers good value to the buyer. Made entirely from 7075-T6 aluminum, the receiver features a black hardcoat anodized finish for added durability and corrosion resistance. This receiver is more of a replacement to the OEM complete lowers.
The lower has been marked for 5.56 NATO ammunition and has a single stage semi-automatic trigger group. The M4-style buttstock and pistol grip makes the receiver great for more general use.
This lower receiver fits perfectly with mil-spec AR-15 uppers. The only thing you might fret about is the price of this product. But the functionalities and good quality obviously overcome this issue.
This complete AR-15 lower receiver has been machined from forged 7075-T6 aluminum with a hardcoat anodized matte black finish. This helps with the strength, durability and aesthetics of your AR-15 rifle. The receiver has been chambered for .223 Remington and 5.56 NATO rounds.
The receiver has a reinforced polymer pistol grip but lacks a buttstock. This may either be a pro or a con on your side. That’s because lacking a buttstock makes it look incomplete. On the other hand, it gives you room for customization and saves you some money compared to other models in this list.
The magwell of this receiver is a bit oversized to help you put in mags easily under stressful situations. This lower receiver is appropriately priced and is perfect for self-defense as well as competitive applications.
This lower receiver from Spikes Tactical is forged from 7075-T6 aluminum to mil-spec dimensions. The complete lower receiver has been hardcoat anodized to resist corrosion, scuffs and scratches. The bullet selector has been stamped and color-coded to notify the shooter about safety and shooting mode.
There’s also a ‘fake’ full auto button on the rifle which obviously doesn’t work or get selected. This is the same product as the Spike AR-15 complete lower receiver mentioned above in this list. The only difference is the lack of a butt stock. This gives you the liberty to add a buttstock of your choice and save some money.
This complete lower receiver has been decently priced and is probably the best stockless complete lower in the market. The matte black finish will obviously suit most rifles, but if you are looking for a colored lower, you might look elsewhere.
How to Install an AR-15 Lower
Installing an AR-15 lower is a fun, if lengthy, task. Follow our video tutorial and the written steps below to make this process a breeze:
- Starting with the trigger group, push the disconnector spring into place. Drop in the trigger assembly and align the pin holes with those of the trigger group. Then insert the pin. Press down on the disconnector to align pin holes. Push the hammer down into the receiver, aligning pin holes. The ends of the spring should lay on top of the trigger pin and not underneath.
- Move on to the trigger guard assembly. Be sure to put your trigger guard in the receiver. Support both sides of the receiver as you start the roll pin. A C-clamp can help support the lower receiver as the other side will drive in the pin.
- Time for the magazine catch. Press the release button into the spring. Screw in the magazine catch on the opposite side of the receiver.
- For the bolt catch, grab your roll pin, plunger, and spring. Place the spring in the hole over the bolt catch and place the plunger above this. Use a punch to start the roll pin. Use pliers to pinch the roll pin until it’s in place.
- Grab your safety assembly with detent and spring, buffer retainer and spring, grip screw, and rear takedown pin with detent, as well as grip and receiver extensions. Cock the hammer and drop the rear trigger assembly into the receiver. Insert the safety detent below the safety selector into the hole, followed by the safety detent spring in the grip. Trap your safety assembly in place and drop the rear takedown detent and then the detent spring. Place the retainer spring into the buffer retainer, and the buffer retainer and spring into your lower receiver. Install the receiver extension.
- Move on to the front takedown pin. Drop the spring into the hole on the lower receiver, and use pliers to help push the detent into the hole. Push in the pin.
- Lastly, for the buffer and spring, cock the hammer and push the buffer spring and buffer into the receiver extension. You’re done!
A complete AR-15 lower receiver is a simple drop-in component which completes your rifle. According to the US law, the sale, purchase, possession and transfer of a complete AR-15 lower receiver is regulated by federal and state laws.
Before choosing a complete AR-15 complete lower receiver, you must focus on its factors like the material, its type, the manufacturer, finish and aesthetics. Aluminum receivers which are hardcoat anodized are more likely preferred over polymer. A complete lower with or without stock might be your preference for customization.