Your ATLAS Handguard will ship with the following:
ATLAS Barrel Nut
ATLAS Barrel Nut Wrench Extension (AR15/M4E1 only)
Barrel Nut Shim Pack
Taper Lock Assembly
Taper Lock Install Tool
The first step to installing your ATLAS Handguard is to securely mount your upper receiver to a vice with the barrel pressed completely into your upper receiver. Ensure that the barrel indexing pin is fully seated into the barrel indexing notch in your upper receiver.
Once your upper receiver and barrel are securely mounted, you will want to apply a non-graphite based anti-seize to the upper receiver barrel nut threads. This ensures that you will be able to remove your barrel nut for any reason down the road.
Next, you will need to tighten your barrel nut to 35-65 ft lbs. using the supplied wrench extension. There are a number of notches running the length of the barrel nut, these serve as a channel for your gas tube; ensure one of these notches is aligned with the gas tube hole in your upper receiver.
*Note if you can not achieve proper barrel nut alignment within the recommended torque range, use any number of the supplied shims to achieve proper alignment.
Once the barrel nut is properly installed, install your gas block and gas tube. Achieving proper alignment can be a little bit of trial and error if you are new to it, so don’t feel discouraged if it isn’t right the first time!
Lastly, you will place your handguard over the barrel and seat it fully against the receiver and barrel nut. Then insert the center portion of the taper lock assembly into the rear taper lock notch in the handguard. Then place both sides of the taper lock assembly into the notch making sure that the angled side of each piece is facing outwards. Then use the supplied tool to tighten the taper lock assembly while holding the assembly in place. Do ensure that the detent in the center of the taper lock notch is engaging with the teeth on the taper lock assembly.
Once the taper lock is tightened down fully you have successfully installed your ATLAS handguard!
* The M5 ATLAS handguards do not include a wrench extension as they utilize a standard armorers wrench.