The AR-15 Homebuilder’s Tool Checklist
You don’t need all this stuff to build an AR, but these tools do make it easier.
SCOUR THE INTERNET AND you’ll find hobbyists that have built AR-15s with a punch and a pipe wrench. On the other extreme, some shooters say you can’t build a rifle in your kitchen with the same reliability or accuracy as a well-known shop.
The truth is, you need more than grandpa’s old wrench to build an AR, but a lot less than a full machine shop. These few key tools will help make your first AR build a success—and the gun a reliable tack-driver. You don’t need everything on this list, but all these tools go a long way toward making an AR build much easier.
An All-Purpose Yoga Mat
You need a place to work and a basic, inexpensive yoga mat rolled across a work bench is as good or better than any gun-specific mat out there. Don’t get me wrong, those gun mats with rifle or handgun schematics are cool, but most of them are black. Not a good color when hunting a tiny dropped spring or matte black detent plunger.
I learned this trick from Matt Compton, at Valley Armament in Sayre, Penn., who built several lowers for me. Check out the videos here and you can see how well dark parts show up on a light mat.
A 4-inch Bench Vise
I built my first AR without a bench vise, but now that I have one I’ll never go back. The vise is used to hold various AR-specific blocks, that will capture the upper or lower in the vise without marring the surface metal. You’re not forging a sword, so you don’t need a big, bad, heavy-duty table vise. This $25 job on Amazon is enough. It probably costs them half that just to ship it to your door.
Wheeler Engineering Delta Series Upper Receiver Action Block
You don’t want to clamp a bare receiver into a vise. This block is what you need to secure an upper in a vise while installing barrels, brakes, gas systems—really any upper work. It’s simple, durable, and inexpensive. There are many similar upper blocks out there. This one is the favorite of the guys at Valley Armament and they probably assemble as many ARs a week as Ruger.
Magpul BEV Block
This vise block works great for lowers. Simply clamp the base of the block in the vise, then slot the lower over the block via the mag well. Easy and sturdy. Great for a home builder’s bench.
Brass and Ball Peen Hammers
It’s tempting to buy and all-in-one hammer and punch set, but in my experience the quality of most of them isn’t great, so I opted for the piecemeal approach. For taping in roll pins where it’s possible to strike a receiver or any metal gun part, I use a 4-ounce brass hammer.
For the heavier work of driving punches without risk of striking your rifle, I like an 8-ounce ball peen hammer, like this one from GreatNeck.
Gunsmith Punch Set
Building and disassembling an AR, you’ll use punches more than anything, so it makes sense to get a good set. This 18-piece kit from TEKTON has four head types for the different kind of pins that need punching.
The solid punch is great for bolt catch pins, trigger pins, and the like, while the reverse taper heads are ideal for roll pins. Starrett also makes excellent punches, but they’ll cost you.
Wheeler Engineering Delta Series AR-15 Armorer’s Bench Block
Think of this like a pillow for your AR. You can lay the upper or lower on it before pounding away with hammers and punches, so your gun parts don’t get crushed into the side of your wood bench. It is most helpful when working on gas blocks or if you need to remove the front sight off an A2 barrel—God help you.
Wheeler Rifle Receiver Lapping Tool
This set includes a drill bit, lapping bar, and lapping compound. It’s designed to true the face of the upper receiver where it meets the barrel. I hadn’t used one prior to this project, but at $22, why the heck not? It comes with enough 220 grit compound to do hundreds of AR-15s. Just don’t go crazy.
You only need to work away the smallest amount of metal. This isn’t an essential step, but recommended for precision builds, if the barrel sits off in the receiver, or if you need to remove metal to better time the barrel nut. Note: this kit is for AR-15 uppers only.
If you’re working on an AR-10 and want to include this step, you’ll need the LR-308 version.
Magpul AR-15 Armorer’s Wrench Multi-Tool
Of all the armorer’s wrenches I’ve tried this one is my favorite—and it’s the only one I haven’t broken yet. Get after a stubborn castle nut, and it’s easy to bend or mar cheap pot metal wrenches. I have three or four busted ones in my shop.
This Rolls Royce model from Magpul fits most AR-15- and AR-10-sized barrel nuts, muzzle devices, castle nuts, buffer tubes, and it’s cut to accept a ½-inch torque drive. Plus, there’s a bottle opener.
½-inch Drive Torque Wrench
It pays to have a good torque wrench. Many home builders don’t go this route, but it’s safer, and smarter, to know and follow your torques. The big one is the barrel nut, which is typically torqued to 30-foot pounds—but check the paperwork that came with your upper and/or barrel to confirm.
Some say a cheap torque wrench is worse than no torque wrench at all. Well, I’ve used a cheapie, like this TEKTON, and haven’t blown a barrel yet. If that doesn’t sound encouraging, CDI—a sub-brand of SNAP-ON—is highly regarded.
A Set of Crows Feet
If the Magpul wrench doesn’t fit your barrel nut, or you can’t leverage it properly with a torque wrench, you might need a crow’s foot. Basically, they’re wrench heads, but instead of a handle there’s a connection point for a 3/8-inch or ½-inch torque drive.
Of the three ARs we built, only one needed a crow’s foot. It’s a specialty item, for sure, but if you need them, you’ll be grateful you have them.
Rubber strap wrenches, which you can find in the plumbing section of most hardware stores, also come in handy when installing a barrel. Sometimes even with the upper in a vise block, you need to apply backward pressure to the upper when tightening the barrel nut.
The strap wrench is a one-trick-pony on the gun bench, but you’ll find 900 other things they’re good for around your home or shop.
Takedown Pivot PIN Tool
Takedown pins can make you crazy. But this $9 pin set takes installing front takedown pins from “throw the damn lower at the wall” maddening, to a 40 second job. If you buy one thing on this list, buy this. It will easily save you 10x the cost in grief.
Needle Nose Vise Grips
A set of small needle nose vise grips, or locking pliers, makes staging and starting roll pins a lot less frustrating, too. The $13 you spend on pliers you’ll more than make up in time saved by not crawling around on the carpet looking for dropped pins. If you plan to build more than one AR, or just want a pro-level tool kit, these hollow-punch roll pin holders from Brownell’s are worth looking at, too.
Wheeler Engineering Delta Series AR-15 Ultra Armorer’s Kit
Don’t want to go the piece meal approach to your gunsmith tool collection? Wheeler will sell you most everything on this list and more for $209. If you don’t like shopping, hit the buy button on this one, and your done.