Shannan Keith
4 min readApr 25, 2016

As long as you take the time to prepare for the job, working with your AR-15 lower receiver parts shouldn’t be a tumultuous task. Figuring out what tools and pieces you need is half the battle — you don’t want to settle in for a day of working on your build just to discover you are missing a key component.

We want your AR-15 building project experience to be as painless and rewarding as possible, so we decided to compile a quick-reference cheat sheet and checklist to help identify and organize the items you will need for successful installation of your lower parts kit. If you have been looking for a simple guide, read on! And don’t forget to save our master list at the end of this post for easy reference in your workspace.

Tools of the Trade

Very few tools are truly “essential” for installing a lower parts kit, and you definitely don’t want to find yourself without them. Although you may not end up utilizing everything included in our list, we wanted to ensure you would be prepared to handle any unforeseen problems.

  • Punch and Drift Set — Whether you choose to purchase a set made from brass, steel or a variety of both, punches and drifts are must-have tools for your lower receiver build. Drift pins can be used to align holes for fastening, while your punches allow you to work with precision while driving tiny objects such as roll pins.
  • Hammer and Mallet — You’ll need to rely on a sturdy hammer when inserting and removing pins. Opt for a rubber mallet when performing tasks with the potential to mar or scar your lower receiver finish.
  • Drill Bits — Have a variety of drill bits on hand to help clear pre-drilled holes in your receiver prior to any parts installation. This procedure should only be done by hand, and with the help of a pin vice.
  • Blocks and Holding Fixture — Use a vise to help hold your parts in accessible positions. Additional tools, such as a trigger guard installation fixture or a hammer block, allow you to work on your lower receiver while protecting more delicate parts from permanent damage.
  • AR-15 Specific Tools — An AR-15 combination wrench will not only assist you with installation of your buffer assembly; it will also be useful when if you begin working on your barrel or with flash suppressors or compensators.
  • Be sure to have a pivot pin installation tool on hand to keep your detent and spring in place while during installation of your pivot pin.
  • Gunsmithing Screwdriver Set — Although you won’t use these tools on a frequent basis during installation of your lower parts kit, you’ll be glad to have them for certain tasks. The specialized build of gunsmithing screwdrivers provides for better protection of both your firearm and your screws, thanks to a hollow-ground design. Instead of tapering at the end like standard screwdrivers, these tools allow the blade to completely fill the slot of the screw, providing more torque and decreasing the chances of slipping or disfiguring the screw head.
  • Oil and Grease — Prior to installation, apply a drop of gun oil to your pins and springs to prevent binding and protect from rust and carbon buildup. Use grease to lubricate metal parts that will contact each other, such as the trigger and hammer pieces.
  • Surface Protection and Blemish Concealment — Use masking tape to cover the surfaces of your lower receiver whenever you are performing tasks with the potential to mar or nick your receiver’s finish. In the event an accident does occur, have a touch-up marker on hand for a quick cover-up.

Select Your Lower Parts Kit

Before you begin installation of your lower parts kit, you obviously have to choose one that will meet your needs. Be sure to examine several different kit types and brands to become more familiar with the variety of parts available on the market.

Selecting a kit labeled as “mil-spec” is a great rule of thumb as a minimum standard. If you prefer to have certain parts that differ from those contained in a standard kit, an “enhanced” part kit may include what you are looking for.

Lastly, be sure to educate yourself on current firearm regulations in your area to ensure your AR-15 is built in compliance with applicable laws. For example, California residents will need to purchase a California Compliant lower parts kit and/or make specific modifications to their AR-15 builds in order to keep their firearm legal.It’s better to be safe than sorry!

Organize the Pieces

You’ll feel much more confident about your ability to install your lower parts kit once you are able to definitively name its individual pieces. Consult an identification chart extensively and frequently as you learn about and organize your kit’s contents.

Once you are able to identify your lower receiver parts, simplify your project further by grouping your pieces according to their applicable assemblies:

  • trigger guard group
  • magazine catch group
  • bolt catch group
  • pivot pin and takedown pin group
  • fire control group

AR-15 Manuals and Educational Materials

With all of the resources available to today’s firearm enthusiasts, educating yourself about installation of the AR-15 lower parts kit has never been easier. How-to videos (add link to your video post and/or to the first post you had me do on how to install the lpk?), gunsmithing books, armorer’s courses and various online references are at your disposal, so pick your favorites and keep them nearby throughout your building process.

Checklist of Lower Parts Kit Installation Must-Haves

  • Punch and Drift Set
  • Hammer
  • Rubber Mallet
  • Variety Drill Bits
  • Vise
  • Trigger Guard Installation Fixture
  • Hammer Block
  • AR-15 Combination Wrench
  • Pivot Pin Installation Tool
  • Gunsmithing Screwdriver Set
  • Gun Oil and Grease
  • Masking Tape
  • Touch-Up Marker
  • Lower Parts Kit (standard or enhanced and in compliance with laws and regulations)
  • Lower Parts Kit Identification Chart
  • Manuals and Educational Materials
Shannan Keith

We believe the AR-15 lower parts kit is the heart of the AR but it’s often neglected. We want to change that. http://en.gravatar.com/ar15lowerpartsco