Building an AR15: 11 tools you’ll need
Building an AR15 has never been as popular as it is now. The parts are readily available and inexpensive, the know-how is readily available, and of course, the process of building your own AR lets you customize it just the way you want.
And let’s face it, building your own rifle can be fun.
Save money, build your rifle?
I’m not sure that building a rifle saves money over simply buying a one of good quality, and the reason is the tools. There are a few AR15 tools necessary to complete your build and others that are just nice to have to make the process easier, but those tools cost money. The higher quality tools can cost a lot of money, which can cut into your build budget significantly.
At the same time, the tools you need to build an AR15 are the same tools that you need to maintain an AR, and they’re certainly not one-use disposable implements. This means that if you are actually going to shoot your rifle you’ll likely need these tools eventually. So the pragmatist in me thinks buying upfront makes some sense for the hard user.
I just finished building my first rifle. I’ve been collecting the tools over time as I’ve needed to work in the various rifles and pistols I already own. I’ll detail out my build in another article but today I want to talk about the 11 tools you’ll need and want to build your next AR15.
This article originally ran in December 2019.
AR15 tools to secure your work
There is nothing worse than collecting all the parts for your epic build and then scratching or breaking your rifle before you even get to shoot it because it wasn’t secured properly. Keeping your pieces and parts solidly in place is an important part of building an AR15. Having your lower and upper securely attached to your bench helps to make sure you are able to reach proper torque specifications — which are important for the long term reliability of your carbine. A solidly held upper or lower will also prevent your work from slipping, hitting the floor and breaking, or losing parts. Finally, securing your AR15 properly provides you with a third hand to keep your work exactly where you want it so that you can focus on your task.
Before you start your build make sure you have the AR15 tools you need for success.
1. Bench // 2. Bench Vice
To me, starting with the foundation makes sense. That foundation is a solid bench with a quality bench vice mounted securely to it. You don’t need anything gun specific here. Any well built and versatile bench makes sense. You can build your own bench (which is what I did) or you can make the purchase at a big box store. The key here is to make sure your bench is sturdy. You are going to be torquing parts to 70 ft-lbs or better so your bench needs to be able to support it.
Your bench vice could also come from the big box store and won’t set you back more than a hundred bucks. Making sure that it can be solidly mounted to your bench is key. I prefer a vice that is bolted to the benchtop.
If you don’t have the space for a dedicated workbench you could explore the possibility of a vice that clamps to a table or countertop. Be aware that this option isn’t as secure and if you aren’t careful you could end up damaging your work and/or your mounting surface.
3A. Magpul BEV Block
BEV stands for Barrel Extension Device and when clamped into your bench vice the BEV from Magpul gives you a secure place to mount your upper receiver. With the bolt carrier group removed, insert the BEV Block into the opening at the bottom of the upper. Slide the upper completely to the rear and insert the polymer pins into the upper and the BEV Block. Then slide the bolt carrier into the back of the upper until it engages past the O-ring on the BEV.
Once the upper is on the BEV you are ready to work on your upper and install your barrel, handguard, or muzzle device.
You can flip the BEV Block over and slide your lower receiver magwell over it to work on your upper. The BEV Block acts line a PMAG with a steel insert to clamp in a vise. I use it with the upper facing up to install parts like the trigger group and other small parts. Then I flip the lower over to install the grip.
3B. Geissele Automatics Reaction Rod
The BEV Block can handle it all, but I use it primarily for supporting the lower. The Reaction Rod from Geissel is a far superior vice for the upper receiver. Once the reaction rod is clamped into the vice, simply slide your upper over the tool. If the barrel is already installed the Reaction Rod will engage with the barrel lugs. If not, installing the barrel is a great first step. While the upper rotates freely on the rod engage the barrel with the lugs on the rod. Mate the upper and the lower and then snug your barrel nut finger tight. Grab your barrel nut wrench and torque wrench and get to work. Because the Reaction Rod engages directly with the lugs of the barrel there is no torque introduced to the upper receiver at all. In my opinion, this greatly reduces the likelihood of damaging the upper.
The reaction rod also has the advantage of being able to hold the upper at many different angles. It is easy to rotate the upper around the rod when installing hand-guard screws or installing rail sections.
Punches for the AR15
Punches are important tools for gunsmithing in general. It makes sense to have the right punches on hand for building an AR15. I have all of the punch sets below and I use them all, but I went a long time with just a good set of Grace brass punches. In fact, I think Grace punches are a good bet across the board.
4. Brass Hammer & Punches
If you can only afford one set of punches, go with brass. Brass punches will get most of the work done that you need to do in building an AR. The soft nature of brass helps to reduce the damage you will do to the finish of your gun. Instead of destroying your work, you will destroy the punches themselves.
So, the photo above shows the GRACE USA 17 Pc Gun Care Tool Set In Nukaf Case. As the company describes it, this is the set that “…was in your grandfather’s gun repair box.” The brass pin punches are manufactured from high-quality CDA 360 hex brass rod and machine-turned and designed for critical work where non-marring and non-sparking are of importance. The set has eight brass pin punches and an 8oz brass hammer. This is only one example of the kind of punches I’m talking about, but you get the idea.
To avoid trashing your brass, you can spend some additional money and get the right punches for each job.
5. Steel Punch Set
There are times when a brass punch just won’t cut it. I remember an episode trying to remove an A2 front sight from an S&W M&P 15. There wasn’t a hammer big enough and my punch shows the wear from the incident. When you need a steel punch you need a steel punch.
6. Roll Pin Starter Punch Set
Roll pin starter punches are a nice addition to your AR gunsmithing tools. These punches are hollow and just the right size to hold the roll pin that you need to install. They act as an additional set of hands to get those pins started (which can keep you from marring that Cerakote job you just paid for).
7. Roll Pin Punch Set
These punches finish the job of setting roll pins. The shape of the tip helps to keep the punch engaged with the pin so you don’t scratch that receiver. They are also a clutch tool for removing roll pins without destroying the pin, the punch, or your work.
8. Center Punch
The proper staking of your castle nut is a key step in keeping your new AR-15 running long term. In my experience, the best way to make this happen is with a center punch. Get a set, they are cheap insurance. In the photo above, you see some DASCO PRO Center punches. According to DP company, they have a precision ground point for making accurate hole starting easier. They’re made of high carbon steel that has been heat-treated and are to be used on metals softer than their point.
Wrenches and Drivers
9. Armorers Wrench
Whether you need to torque your castle nut or your barrel nut, an armorers wrench is an important tool. It’s hard to go wrong with Magpul’s wrench as it can do about all of it without breaking. It engages both stock and pin-style barrel nuts and works with a 1/2″ torque wrench.
It can also open your beer.
10. 1/2″ Torque Wrench
The Magpul armorers wrench has a handy square hole that allows you to attach your ½” drive torque wrench. Most proprietary barrel nuts come with a wrench that allows for the same. There is a reason for this: Torquing your build properly is important to make sure it remains reliable and to ensure you don’t go all Lincoln Hawk on your rifle parts.
You need a torque wrench for your barrel nut and your castle nut. Get one. Use it.
11. Interchangeable Tip Driver Set with Hex and Torx.
Like a brass punch set, a decent driver set with a straight blade, Phillips, hex, and Torx make a ton of sense for your build. You probably won’t use the straight blade and Phillips tips for your AR, but they come in handy when working on lots of other guns. For this reason, buy a set specifically made for work on guns. The screw slot sizes and tips will match exactly, keeping you from scratching your blaster.
For the AR, hex and Torx pits are key AR15 tools, especially when dealing with higher-end builds that have threaded bolt catch pins and when mounting optics.
Bonus #12, Detent Saver: AR15 Pivot Pin Installation Tool
Those that have built an AR know that the trickiest part of the build is avoiding the launch of tiny detents and springs. I think the pivot pin install is the hardest of all to pull off without sending parts into orbit. This handy tool helps to capture the front takedown pin detent and spring in place so that the installation of the pin is much easier.
It isn’t a necessary tool, but making the purchase is less frustrating than ordering a new detent…
Are You Headed Toward a New Hobby?
Shooting guns is a hobby. Building guns isn’t part of that hobby. Instead, it is a whole new hobby that is loosely connected to the blasting.
There are tons of reasons to consider building your own AR. Make sure that when the scale tips to a green light on your first build you have the AR15 tools you need to make it happen. If you already own some ARs it makes sense to start collecting those tools now so you can keep your gun running. If you are just getting into the AR game, there is no better way to learn about the platform than building your own gun. As long as you have the tools.
For those of you that have built rifles before, what am I missing? Do you have a favorite tool or an alternative to the armorers’ tools I talked about here?
Share in the comments and happy building!
If you enjoyed this article, take a look at the rest of Paul Carlson’s informative articles on The Mag Life.
Paul Carlson, owner of Safety Solutions Academy, is a Professional Defensive Shooting Instructor. He has spent the past decade and a half studying how humans can perform more efficiently in violent confrontations and honing his skills as an instructor both in the classroom and on the range.
Through Safety Solutions Academy, Paul teaches a variety of Critical Defensive Skills courses in more than a dozen states annually. Courses range from Concealed Carry Classes to Advanced Critical Defensive Handgun Courses and include instruction for the defensive use of handguns, rifles and shotguns. Safety Solutions Academy regularly hosts other industry leading experts as guest instructors to make sure that SSA’s students have the opportunity for quality instruction across a broad range of Critical Defensive disciplines.