Tech Tip: How to Install the LAW RAP

Synopsis

Caleb from Brownells kicks off this tech tip video with a walkthrough of how to install the Law Tactical Rail Adapter Plate (RAP). This installation is designed specifically for use with the Law Tactical ARIC, a bufferless bolt carrier system for AR-15 platforms. If you're looking to add a 1913 rail stock or brace to your build, this guide is for you.

What You Will Learn

Viewers will learn how to install the Law Tactical Rail Adapter Plate (RAP) onto an AR-15 lower receiver equipped with the Law Tactical ARIC system, including required tools, torque specs, and the step-by-step process for prepping, aligning, and securing the RAP. 

Benefit

By following the video, viewers gain the ability to expand their AR-15’s customization options—specifically, enabling the attachment of a 1913 rail stock or brace directly when using the ARIC—all while ensuring a precise, secure installation. 

What is the Law Tactical RAP?

The RAP, or Rail Adapter Plate, is a 1913 adapter that mounts on the rear of your AR-15 lower receiver. However, it's only compatible with the Law Tactical ARIC system. The ARIC replaces your traditional buffer and buffer tube system, previously usable only with folding stock adapters. The RAP now expands your options by allowing you to run a 1913 stock or brace directly with the ARIC.

Tools and Parts Needed

To get started, you'll need a standard AR-15 lower receiver. In this demonstration, Caleb uses an Aero Precision M4E1 Pro lower. The RAP kit comes with the adapter itself, a locking nut, and a screw. You'll also need a 5/32-inch driver and a Law Tactical installation tool, though the Armor Tool is recommended for repeated use or professional setups.

Disassembling the RAP

The RAP arrives as a solid steel assembly. Begin by removing the single screw at the bottom using your 5/32-inch driver. Once the screw is out, the rail separates from the housing, exposing the internal structure you'll mount to the receiver.

Prepping the Lower Receiver

If you've previously installed a Law Tactical folding adapter, this process will feel familiar. Start by inserting the detent and spring for your rear takedown pin. Then align the RAP to the receiver, making sure the extruded section keys correctly into place.

Thread the supplied nut into the receiver’s extension threads. It uses a standard 1 3/16 x 16 thread pitch. Use the Law Tactical tool or Armor Tool to snug it down.

Installing the RAP Base

Torque is important here. If you're using a torque wrench, the spec is between 5 to 7 foot-pounds. Avoid overtightening, especially the small tensioning screw. This screw is only meant to apply light tension to the locking nut. Overdoing it can bend the nut and cause interference with the ARIC flange.

To secure the tensioning screw, apply a dab of blue thread locker to the threads. Insert it into the hole and tighten it just until it makes contact. A gentle snug is all that’s needed.

Reattaching the RAP Rail

With the base secured, reinstall the RAP’s rail section by aligning it and threading the main screw back in. Thread locker can be applied here as well for added retention.

Installing the Law Tactical ARIC

No buffer or buffer retainer is needed with the ARIC. To install it, pull the charging handle slightly and insert the ARIC like a normal bolt carrier group. Make sure the curved tail (the flange) is facing upward and aligned with the groove under the charging handle.

Close the upper and lower receivers, pushing the flange in as you do. The flange should seat flush against the back of the RAP.

Verifying Correct ARIC Fit

A good way to verify proper fitment is by checking the location of the rear pin on the ARIC. It should sit directly under the marked “A” area. If the pin is too far forward, it means something didn’t seat properly, often due to overtightening the tensioning screw.

Attaching 1913 Stock or Brace

Now you're ready to attach a 1913 stock or brace. Caleb uses a Midwest Industries brace and stock for demonstration. These attach like any other 1913 accessory and are secured with the appropriate driver.

Final Thoughts and Support Info

The installation is straightforward but requires attention to detail, especially with torque and alignment. The Law Tactical RAP expands the flexibility of the ARIC system by allowing use with 1913 accessories. If you run into issues or need help, the Brownells tech team is available for support. Drop a comment below or reach out directly if you need assistance.