FRB Installation Guide - Redacted Arms

FRB Installation Guide

The Redacted Arms FRB is a TRUE DROP IN for MOST Ar-15 platforms. Most installs are straightforward, but trigger compatibility vary.

A full-auto / M16-style bolt carrier group (BCG) is required for the FRB to function.

Installation Video

Installation Steps

Prepare the Lower

Ensure the firearm is unloaded. Remove the Allen key grip screw, pull off the pistol grip, and remove the spring. Drop the detent out and set it aside — you will reuse it. Remove your existing safety selector and set it aside.

Install the Selector

Insert the included safety selector into your lower.

Reinstall the Detent and Grip

Flip the lower upside down and drop the detent in pointy side down. Place the spring into the pistol grip, reinstall the grip, and make sure the spring drops into the detent hole. Tighten the grip screw fully.

Insert the FRB

With your hammer cocked, Insert the FRB over top of your safety selector. Ensure that the lever on the FRB is forward and touching the hammer. Once the FRB is in the lower you can reattach your upper and preform a function test.

Function Check

With the upper attached, cock the charging handle and run through each position:

  • Safe — Pull the trigger. The hammer should not fall.
  • Fire — Pull the trigger. The hammer should fall normally.
  • Active Safety (3rd position) — Pull the trigger to drop the hammer. Hold the trigger down, cock the charging handle again, the BCG will move to the rear to simulate firing. The trigger should reset as the lever travels back. Release the charging handle forward. Once the BCG enters battery, the trigger should break cleanly.