Step U2: Forward Assist Installation
Objective: In Step U2 of upper receiver assembly, we will install (or replace) the forward assist.
NOTE: This step does not apply if you are either 1) using an assembled upper and are not replacing the forward assist, or 2) building on an upper receiver without a forward assist (e.g. an AR-9 on the Aero Precision EPC platform).
Tools Required
1: Applicable for Aero Precision Enhanced upper receivers only. If you are using any other upper, you will need a 3/32″ roll pin punch and hammer.
2: Applicable to standard AR upper receivers that utilize a standard roll pin instead of a threaded pin.
Components Required
| Quantity | Component |
|---|---|
| 1 | Upper Receiver |
| 1 | Forward Assist Assembly |
| 1 | Threaded Forward Assist Pin (incl. with Upper Receiver)1 |
| 1 | Forward Assist Roll Pin2 |
1: Applicable to Aero Precision Enhanced upper receivers only. If you are using any other upper, you will need a 3/32″ roll pin.
2: Applicable if NOT using an Aero Precision Enhanced upper receiver.
Instructions:
Step U2.0: Remove Existing Forward Assist Assembly (replacement/upgrade only)
If you are replacing your forward assist assembly (or need to remove the forward assist assembly for any other reason), first ensure the firearm is unloaded.
Threaded Pin (Aero Precision Enhanced):
Place slight pressure on the forward assist while you back out the threaded pin using a 1/16″ hex wrench. Remove the threaded pin and the forward assist assembly and spring.
Standard Roll Pin:
While applying slight pressure on the forward assist, tap the forward assist roll pin out of the upper receiver using a 3/32″ roll pin finish punch. Remove the forward assist assembly and spring.
Step U2.1: Lubricate the Forward Assist Assembly
Apply a thin layer of wet lube to the shaft of the forward assist assembly.
Apply a drop of wet lube to the interface of the pawl and body of the forward assist assembly using a needle dropper.
Step U2.2: Install the Forward Assist Spring
Place the forward assist spring over the forward assist assembly.
Step U2.3: Install the Forward Assist Assembly onto the Upper Receiver
Insert the forward assist assembly into the applicable pocket in the upper receiver, with the pawl hinged inward.
Step U2.4: Install the Forward Assist Pin
Threaded Pin (Aero Precision Enhanced):
WARNING: DO NOT USE THREAD LOCKER.
While depressing the forward assist, insert the threaded pin into the upper receiver. The pin will pass along the flattened side of the forward assist assembly shaft and back into the upper receiver.
Carefully begin threading the threaded roll pin into the upper receiver. Be careful not to cross-thread.
Hand tighten.
Standard Roll Pin:
Tap the roll pin into the top roll pin hole in the upper receiver using a 3/32″ roll pin starter punch.
While depressing the forward assist, drive the roll pin into place using a 3/32″ roll pin finish punch. The roll pin will pass along the flattened side of the forward assist assembly shaft and back into the upper receiver.
Step U2.5: Function Check
Depress the forward assist until it bottoms out. You should not encounter any resistance (except for that of the spring). You should see the pawl emerge into the upper receiver (where the bolt carrier group will be installed later).
If the forward assist does not function properly, disassemble and inspect.