The AR-15 forend tube (handguard) can be user-installed or it can be done by a gunsmith. The following is a general guide and may vary to the individual rifle.
Recommended Tools: Proper sized pin punch and hammer, AR armourers wrench (if you need to remove the existing barrel nut from your upper receiver), proper action holding block and Hogue black gun wrench (included).
1. Before starting, make sure rifle is unloaded. All operations must be carried out in a manner that will not damage or mark the rifle.
2. Remove existing gas block and forend per manufacturer's instructions.
3. Separate the Hogue tube by un-threading the barrel nut, separating it into two pieces. The Hogue Black Gun Wrench (included) and a proper AR-15 action block are recommended to eliminate the possibility of damage to the tube or your rifle.
4. Lubricate the threads on the barrel nut and on the surface it will tighten against. Hand tighten the barrel nut and then tighten according to the instructions below.
5. Follow type A for specific instructions:
A. Low Profile Gas Block, with Extension Tube, with AccessoryAttachment: Install the low profile gas block and gas tube. Make sure the jam nut is screwed all the way onto the extension tube. Screw the Extension tube onto the barrel nut until it stops. Back the extension tube off until the first row of threaded holes lines up with the center of the upper receiver rail. Tighten the jam nut against the barrel nut making sure your alignment does not change. Screw the forend tube onto the end of the extension and tighten. Go to next step.
6. Check for proper function and test fire the rifle.
Use Instructions For The Hogue Black Gun Wrench
1. The Hogue Black Gun Wrench that is supplied is made out of an extremely strong and durable polymer that will not break under normal use. Required safety equipment consists of safety glasses and set of work gloves.
The complete wrench is comprised of two parts labeled wrench A and wrench B. The wrench fits two different dimensions: 2" diameter for the barrel nut and 2-1/8" diameter for the extension jam nut. There are directional arrows moulded onto the surface labeling which directions the wrench should be turned.
2. To install the barrel nut first remove the charging handle and bolt carrier group from the upper receiver. Second, remove the existing barrel nut. It is important to lubricate the threads and bearing face of the Hogue barrel nut and the flange face of the barrel extension with assembly tube. Third, clamp the upper receiver into a vise using an upper receiver vise block and remove the existing barrel nut. It is important to lubricate the threads and bearing face of the Hogue barrel nut and the flange face of the barrel extension with assembly lube.
Next, hand tighten the nut onto the receiver and inspect the gas tube hole alignment. One hole in the barrel nut must be aligned with the hole (1) in the the upper receiver for the gas tube to pass through. If 1/4 or more of the upper receiver hole (1) is exposed through the barrel nut hole (2) it is recommended that you bypass that hole and rotate the nut to the next one (3). This will properly torque the nut within the desired specification of 35-85 ft lbs.
3. To attach the wrench to the barrel nut, insert the arm of the 2 inch side of wrench A into the centre opening of wrench B. Leave the arm of wrench A resting outside and below the opening of wrench B.
Slide the tool over the barrel nut knurling observing the directions of the arrows on the tool. Lever the opening of wrench A over the arm of wrench B making sure that both parts of the tool are properly aligned. This is purposely made tight so that the wrench has maximum hold onto the barrel nut. To rotate the nut, first apply force to wrench B. As you tighten the nut, constantly check the gas tube hole alignment. If the nut will not tighten any further, loosen then tighten the nut a few times before the final hole alignment. If you bypass a hole you must proceed to the next one for proper toque.
4. To remove a Hogue barrel nut, reverse the direction of the tool. For the extension lock nut, use the tool in the same manner using the 2-1/8" side.
If the tool slips on the knurling, get a piece of emery cloth and place it between the tool and the barrel nut with the abrasive side facing the wrench.
Specific part number information: 'Hogue 15067 - Knurled Aluminum 9.5" OAL 3 Gun Free Float Forend Extension with Accessory Attachments'