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For those who like to tinker. Adjustable gas block? Just want to clean? Change a gas port size? On, off and on again in a minute.
When designing a rail, we started with our customer base in mind. We have been to the range doing research and development and grew tired of undoing screws and having to carry a few tools to tune the rifle the way we wanted. So we put an end to it. This isn't a tacticool gimmick, this is for you, the builder.
If you notice, our barrel nut centers on the inside of the rail extrusion. This is our anti rotation, no tabs sticking out, no extra pieces to fiddle with. Just get the barrel nut right and you're good to go.
We chose to use a two piece system to cinch the barrel nut down. We have an outer sleeve, that aligns the rail and locates the rail with a pin as well as a steel barrel nut with 1.25" flats for torquing the system down.
Unlock the cam clamp to begin the disassembly process. This should be torqued to approximately 15 inch lbs when closed.
The takedown pin is the second step of the puzzle. Alone it is enough to keep the rail on and clamped well enough that it isn't necessary to be clamped. The clamp removes every drop of wiggle from this system.
The system works together to create a sleek and secure locking mechanism for your AR-15 while allowing you the ability to clean, modify, or just show off.
Take a second to familiarize yourself with your handguard. Both barrel nut and the alignment tool are contained in the assembly.
Familiarize yourself with the cam clamp and takedown pin.
The alignment tool is held captive by two vitton O-rings, the same used in an M4 bolt assembly, remove the alignment tool from the handguard assembly.
The first step involved with assembling the QDS handguard is to remove the barrel nuts from the assembly. We recommend you thread the handguard on to an upper receiver to do so. You must unclamp the cam lock and remove the take down pin just like you would on your lower receiver. Then when the handguard is secured to the upper you can pull it off. This fits tight by design. We like our handguards snug. Remove all components from the upper.
When everything is removed, you can then put your barrel into the upper receiver, make sure it fits the way you would like and apply a drop of anti-seize to the upper receiver's threads.
Thread both of the barrel nuts onto the upper receiver, make sure the smaller barrel nut has at least three threads exposed.
The larger of the two barrel nuts should come in contact with the upper receiver eventually. Only hand tighten this, it is just to ensure the gap is as small as possible between the upper and the lower.
Unscrew the first barrel nut just enough to slip the alignment tool in. Make sure the alignment tool fits through the upper receiver and the barrel nut.
Begin tightening the smaller barrel nut by hand, this will cinch the barrel nut into the barrel.
Torque your barrel nut between 35-50 ft lbs, the alignment pin will prevent the rotation of the barrel nut.
You're going to have to tap out your alignment pin with a punch or a gas tube, torquing it will have pushed it against the inside wall of your upper receiver. After it is removed, you can fit your gas block if you'd like.
Make sure your takedown pin is out and your cam clamp is open. This is the part where you get to install your rail. Slide it over the barrel nut, it should fully cover the barrel nut.
Torque your cam clamp to approximately 15 in-lbs DO NOT torque it to ft lbs. You should be able to push on the barrel and handguard and have no "clicking" feeling when torqued properly.
The first time or two you do this you may want to lightly tap on the takedown pin if it isn't aligned. It will wear in and become a bit easier to align with the barrel nut. It also helps if you do this last step upside down.