Revised August 11, 2010

Make sure weapon is unloaded.

Tools required:

*5/32” hex key
*1/8” hex key
*Blue Loctite or equivalent

If retrofitting an existing upper assembly, remove existing handguard and delta ring leaving the factory style barrel nut in place.

If assembling a rifle from the ground up, a factory barrel nut will be required to be installed and properly torqued.

If using a low profile gas block, whether covered by the tube or exposed, the gas block can be installed at this point.

If using a front sight gas block, it must be secured in place after the handguard is installed.

Place the two halves of the Handguard System Clamp around the barrel nut and thread the four included socket head cap screws partly in, leaving loose enough to allow some movement in the Clamp.

Slide the end of the Handguard Tube with the four holes over the Clamp and loosely install the four included button head screws. (If permanently installed muzzle device prevents the Tube sliding on from the muzzle end of the barrel, it can be placed from the rear before the Clamp is installed.) The holes will only align in one position, assuring proper positioning.

Once the Tube is over the Clamp, position the assembly so that the clamp screws are facing the bottom of the rifle and snug all screws evenly, maintaining an equal gap between Clamp halves. Lastly, tighten all screws evenly to prevent movement of Clamp.

If a front sight gas block is used, it can now be secured in place. Extended Apex Handguard models have an access hole for pinning the front sight gas block to the barrel.

After final safety and function checks, it is recommended that one screw at a time be removed and secured with Blue Loctite or equivalent, and as with any piece of equipment the screws should be checked periodically for tightness.


Rail Installation:

Top Rail:
Use included special flat head screws to attach Rail directly to the Tube using the appropriate holes in the top of the Tube.

Accessory Rails:
Place the Rail Nuts at the desired location inside the Tube and insert screws thru the Rail and Tube to the Nuts, adjust to position and tighten. The Rail Nut is designed to deform slightly when drawn against the inside of the Tube, thus securing the Rail from loosening inadvertently; however, Blue Loctite may be used as a further precaution.