Quick Tip: The Lower Alignment Tool "LAT"

Introduction 

In this Brownells Quick Tip, Caleb walks you through the correct use of the LAW Lower Alignment Tool during an AR-15 lower receiver build. This tool is essential for anyone who wants to perfectly align the receiver extension with the lower and stake the castle nut with precision.

Introduction to the LAW Lower Alignment Tool

Caleb introduces the LAW Lower Alignment Tool, designed specifically to help builders properly align their AR-15 receiver extensions. Misalignment may not always cause immediate issues, but over time it can impact reliability and make staking more difficult.

Unboxing and Initial Impressions

Opening the box, Caleb notes that the LAW tool comes with clear machining, quality finish, and a simple design. It looks and feels like a purpose-built tool designed to make the buffer tube installation process cleaner and more professional.

Required Tools: Geissele Reaction Block

Before jumping in, Caleb mentions one critical component for using the LAW tool properly — the Geissele Reaction Block. This block locks your lower receiver in place and is necessary for stability while tightening and staking parts.

Preparing the Lower Receiver

The lower receiver must be stripped down before beginning. Caleb removes any existing hardware and ensures the receiver is clean and ready for component installation.

Removing the Grip for Installation

To install the LAW Lower Alignment Tool, the pistol grip must be removed from the lower. This step is important because the LAW tool mounts using the grip screw hole.

Setting Up for the Build

With the grip removed and the tool mounted, Caleb positions the LAW tool properly and ensures the castle nut and receiver extension are prepped. Everything should be ready for assembly with all parts aligned on the bench.

Installing the Receiver Extension

Caleb carefully threads the receiver extension (buffer tube) into the lower, stopping just shy of where the buffer retainer pin will sit. This allows fine-tuned alignment before torquing it down.

Installing the Castle Nut

Next, the castle nut is threaded onto the receiver extension and moved into position. Caleb makes sure it is installed in the correct orientation and flush with the endplate.

Mounting in the Vise

With everything loosely installed, the entire lower receiver is mounted into the Geissele Reaction Block. This provides the stability needed to torque the castle nut without shifting the alignment.

Using the LAW Lower Alignment Tool

Caleb walks through how the LAW tool ensures proper alignment between the buffer tube and the lower receiver. Once secured, the tool guarantees the extension is parallel to the lower and perfectly positioned for staking.

Aligning Receiver and Extension

He confirms the receiver extension is properly aligned with the tool. This step eliminates guesswork and makes it easier to avoid canted buffer tubes, which can interfere with the operation of the bolt carrier group.

Tightening and Securing

With everything aligned, Caleb tightens the castle nut to spec. The LAW tool holds everything in place, allowing for confident torqueing without slipping or misalignment.

Staking the Castle Nut

Now that the castle nut is torqued down, Caleb stakes it using a punch. Thanks to the LAW tool’s alignment, he is able to create solid, centered stakes quickly and efficiently.

Removing the Tool After Use

Once staking is done, the LAW tool is removed. Caleb notes that reinstallation of the grip is the final step, and no parts were harmed or marred during the process.

Final Thoughts and Tool Impressions

Caleb wraps up by saying that the LAW Lower Alignment Tool is a must-have for serious builders. It saves time, eliminates frustration, and improves the final result of your AR-15 build. Whether you’re working on a folding stock adapter or a standard buffer tube setup, this tool makes the job easier.

Viewer Questions and Tech Support Info

As always, Caleb invites viewers to drop questions in the comments or reach out to Brownells' Tech Support team for personalized help. The LAW Lower Alignment Tool is available on Brownells.com and is ideal for your next build or shop bench upgrade.