AR 15 Lower Receivers

Looking for an AR 15 lower receiver for your next build? Below we have some of the highest rated options available, along with ratings, reviews, and more. Because of regulations (which we go into more below) a FFL is required to buy the lower receiver online. This can be easily done, and our partner site (which you will go to once you click on your favorite lower below) will help you take care of that process. Further down this page, you can see the massive efforts it takes to build your own – which is why we recommend purchasing a full lower.

Without the receiver, operation of a gun or rifle is impossible. The law views the receiver as the firearm itself and requires a serial number on it – making it the controlled part of the rifle. In the AR 15’s case which has 2 parts (the upper and the lower), the lower receiver is controlled.

The AR 15 lower receiver is basically a puzzle with different parts and multiple alternatives for every one of its components which makes it very convenient for customization for every user. However due to its endless modification possibilities you have to know the function and assembly of each part to safely improve your rifle.  Just like in assembling your upper receiver, there are plenty DIY website tutorials for assembling lower receivers, but there is still no substitute for trained professional or experienced personnel that can effectively teach you the best practices for assembling your AR 15 lower receiver.

In order to safely build or assemble your AR 15 lower receiver, you have to have the necessary tools at your disposal, your gun tool box has to have at least a bench vise, AR 15 lower receiver vise block, roll pin punches, roll pin holders, small brass hammer, needle nosed pliers, razor blade, Roll pin pusher , block of wood, castle nut wrench, pencil (mainly due to the small eraser end, since it’s rubber, this is for installing the magazine and buffer retainer), electrical tape and gun oil.

Another aspect of the rebuilding your AR 15 lower receiver is the observance of discipline and organization of the components, this is due to the many and small parts of the lower receiver, you have to be organized so that you will not lose any piece. Most assembly professionals segregate the pieces into large and miscellaneous pieces, pins and detents, and springs.

The components of the first category are usually the bolt catch, buffer, buffer retainer, castle nut, hammer, disconnector, lower receiver end plate and extension, magazine catch, magazine catch button, pistol grip, pistol grip screw, pistol grip lock washer, safety selector, trigger and trigger guard.

In the Pins and Detents are bolt catch buffer, bolt catch roll pin, hammer retaining pin, pivot detent, takedown detent, takedown retaining pin, trigger guard roll pin, and trigger pin.

While in the Springs are the bolt catch spring, buffer spring, buffer retainer spring, disconnector spring, hammer spring, magazine catch spring, pivot pin detent spring, safety selector spring, takedown pin detent spring, and trigger spring.

Note of the large number of parts that is why it is important that you take note or monitor the items, you can also have your own way of organizing the parts as long as you can keep track of them effectively.

If you elect to follow an internet DIY (Do It Yourself) guide, make sure that it is made by a reputable author on a reputable site, and additionally make sure that you follow every instruction to the letter for your safety and your rifle’s safety. AR 15 lower receivers can easily be built from scratch, but it’s always best to buy them already completed.

Hey guys, I'm Specialist Paul Bauer. I'm an active duty member of the U.S. Airborne Infantry and have served almost a year in Afghanistan. While I was there, I developed a strong passion for AR-15's and it stayed with me to this day.
I've built this site to help share my passion of AR-15 building with you! If you want to reach out to me personally, the best way is to e-mail me at