Since I posted the Parallax Tactical FFSSR Rails in the announcement here, I decided to obtain one of these rails. So far I've been impressed with how slim the rail is. The middle cutout area is also compatible with all Magpul accessories including rail sections. These rails are available at Weapon Outfitters and AIM Surplus. Parallax Tactical is still working on their website but follow them on Facebook.

Manufacturer: Parallax Tactical

Item to be Installed: FFSSR 13" Rail

Purpose of Item: The Parallax FFSSR single-piece aluminum foregrip delivers one of the slimmest profiles in the industry. The middle cutout area is designed to be compatible with all MagPul accessories, including rail sections. Rails where you need them—not in your way.

Parts used for this Upper Receiver Build:

Parallax Tactical FFSSR 13" Rail
Parallax Tactical PXR Super Light Low Profile/Lightweight Gas Block
Midwest Industries Billet Upper
Centurion Arms 14.7 CHF Barrel
BCM Gunfighter Mod 4
BattleComp 1.0

Tools Needed:

Armorers wrench
Torque wrench
Vise
Action Block
Allen wrench


Thanks to Uncle Stickman for the pictures.

Before starting any installation or work on your AR15 platform, make sure you follow the basic safety rules and clear your weapon of any magazines and ammunition. Double check to ensure your weapon is safe.

First you want to remove your existing flash hider, handguards, and front sight/gas block and tube. You will need your standard armorer wrench, torque wrench, a vise and action block to complete this. Or if you're building a new upper your layout should look like this:




The kit also comes with allen head screws and shims for the barrel nut.



You'll then want to install the supplied proprietary barrel nut over the barrel. Make sure you apply some moly grease to the threads of the upper receiver and barrel nut first. This helps protect the threads.



Using your armors wrench and torque wrench tighten the barrel nut to 30ft-lbs. Then check alignment. You will want the row of mounting holes to be about halfway inline with the gas port hole in the upper receiver. These will twist to the 12 o'clock position when the barrel nut is completely tightened.

If no holes are aligned, remove the barrel nut and add a shim. Then using your torque wrench tighten the barrel nut between 30 to 80 ft-lbs to time the barrel nut. The mounting holes should be at 3 and 9 o'clock.



Install your gas block and gas tube.



Slide the FFSSR over the gas block and gas tube. Confirm the rail is properly aligned. You should see the screw holes in the rail line up with the barrel nut mount holes align.



Using a torque wrench set to 50 inch-lbs take the 4 mouting screws and install them loosely at the 3 and 9 o'clock positions. Parallax recommends applying some rocksett or other thread locking compound on them before installation.

Then set your torque wrench to 30 inch-lbs and install the 2 low head mounting screws at the 6 o'clock position.



Parallax recommends tightening the 3 and 9 o'clock screws to 50 inch-lbs in an alternating pattern:

Rear Right
Front Left
Front Right
Rear Left

Your installation is complete!