Tools that Hold Stuff (Vices and Blocks)
You cannot effectively build an AR properly without a way to secure the components during assembly.
R: Required
r: Recommended
O: Optional
Bench Vice (R)
A bench vice is essential. You must secure the receivers properly during torquing of certain components, and the bench vice is half of the equation (the other being receiver “action blocks/rods”).
We recommend a bench vice that has at least 3″ wide jaws that can open at least 3″ wide. A pivoting vice gives you the option to turn the piece for a better work angle.
We use a couple of different vices (Harbor Freight and Yost) and they both work well.
We recommend a set of magnetic vice jaw inserts to protect your gun if you need to clamp anything directly in the vice.
Upper Receiver Block/Action Rod (R)
The upper receiver MUST be properly secured during installation of the barrel nut and the muzzle device. Failure to do so may result in damage to your upper of the barrel indexing pin, and could result in misalignment of gas system. We secure the upper using a tool called the upper receiver action rod.
In our eyes, the only ideal upper receiver action rod is the Midwest Industries Upper Receiver Rod. With the charging handle and BCG removed, this tool inserts into the upper receiver. The star lug engages and aligns the barrel extension star chamber. The action rod ridge engages the channel in the top of the upper receiver to prevent rotation during torquing of the barrel nut and muzzle device (this sets it far ahead of the Geissele Reaction Rod).
We do not recommend any type of “clamp around the upper” style receiver blocks. These do absolutely nothing to ensure alignment of the barrel or to prevent shearing off the indexing pin.
Lower Receiver Block (R)
We use three different lower receiver blocks for three different reasons.
Mag Well Block
The first block that we use is only used to hold the receiver during installation of small parts. For this purpose, we use a mag well vice block. There are many options and variations. One of the best options is the Midwest Industries Lower Receiver Block. It comes in AR-15 and AR-10 versions and includes many features beyond a vice block, including a gas tube installation jig for securing your gas block while you install the gas tube roll pin. There are other, simpler designs, like the Tacfire Lower Receiver Vice Block, which is just as effective at holding the lower in place, but lacks some of the other useful features.
Torquing Block
The lower receiver needs to be properly secured when torquing the castle nut. A receiver block that engages the lower receiver AND the receiver extension is required for carbines and pistols. There are a couple of options for this. We use the VISM Lower Receiver Vice Block. With the pistol grip removed, the receiver is supported, while the clamping mechanism for the receiver extension ensures correct orientation and alignment with the receiver. It is generally compatible with all conformant AR lower receivers (AR-15, AR-10, AR-9). The more expensive option is the TechCo Receiver Extension Tube Jig, ringing in at $329 (vs. under $50 for the VISM). In our opinion, the TechCo product isn’t worth the added cost for no additional functionality.
Staking Block
When staking the castle nut, the receiver extension needs to be properly secured and supported. This CAN be achieved using the VISM or TechCo style vice blocks, though it is a bit more awkward to get the staking angle. If you are serious about building ARs, the best product for staking the castle nut is the Geissele Reaction Block. Because this tool only grips the receiver extension, the receiver can be rotated 360 degrees (in 90 degree increments). This feature alone makes staking the castle nut much easier. Note that, because it does not secure/align the lower receiver, the Geissele Reaction Block is NOT ideal for castle nut torquing.
Gas Tube Roll Pin Block (R)
During installation of the gas tube roll pin, the gas block should be properly secured. It is technically possible to install the gas tube roll pin without one. Any time we have tried to do this operation without a fit-for-purpose tool, we fumble trying to prop up the gas block with various objects while we attempt to start the roll pin while also keeping the gas tube properly aligned. Spend the $10.
There are a couple of blocks out there from major brands. We will say that they ONLY fit “standard” low profile gas blocks. We actually use a 3D printed block that we bought off of Etsy and it works great.
Note that if you purchase the Midwest Industries Lower Vice Block, it has a built in gas tube installation block, which also happens to be the most universal design that we have found.
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