View Full Version : Daniel Defense Lite Rail install guide and pictorial review

22 June 2007, 10:41
Weapon System: AR15/ M16

Manufacturer: Daniel Defense (http://www.danieldefense.com/)

Item Installed: Daniel Defense 7.0 Lite Rail (http://www.rainierarms.com/?page=shop/detail&product_id=440)

Purpose of Item: A free floating rail allows for multiple attachment points of equipment, to include optics, vertical foregrips, lights, lasers, and other items. A FF rail also allows for better accuracy by the barrel not being touched by the forearm. For many users, it is more a matter of a stable handguard/ rail that will not rattle or wiggle under hard use than it is absolute accuracy. There are several different styles of Free Float rails. This is a single piece rail as opposed to some which are two piece.

It may be of interest to the reader that Daniel Defense was awarded the SOCOM SOPMOD RIS II rail contract. This rail attaches in the same manner as the DD Lite series of rail, and was shown to be secure, and ran the trials without any incidents or problems. While there might be higher praise for a rail system, I certainly canít think of it. The military version of this rail includes a detachable lower rail, and mounts for a M203 grenade launcher. Daniel Defense has these available for sale on the commercial market if this is something you find interesting.

Tools Needed:
Receiver blocks
Barrel wrench
Loctite (new model lite rails come with loctite on the screws)
DD barrel nut wrench

Items Included:
Allen head cap screws with thread locker
Barrel nut
Barrel nut collar
Rail covers

The Daniel Defense Lite Rail (DD 7.0 Lite) is a Free Floating Rail designed to be installed and used on a standard AR15/ M4 carbine. This guide does not act as a substitute for real world knowledge, and is not designed to turn the reader into a professional ďgun plumberĒ. However, it is my belief that the overall installation process is simple enough for anyone who is familiar with the AR15, and has a basic level of skill with simple hand tools. This is based on my own method of installation, and all liability is with the end user. If you stab yourself, shoot yourself, or find some other manner of getting yourself hurt, you are responsible for your own actions. If you have doubts, get help.

NOTE- The rail used in this installation has been previously installed, as well as used on a training weapon. While you may see scratches or a little wear, this was caused by me, and it isn't how the rail comes out of the box.

22 June 2007, 10:42
With the above out of the way, let’s make sure that we are starting with an empty weapon. Once that is done, remove the upper receiver, pull out the charging handle and bolt carrier group (verify the chamber is empty a second time), and lastly, pull off the handguards.

You should now be looking at something similar to the below picture.


Take your box with the DD 7.0 Lite rail. You should find a rail, barrel nut collar, barrel nut, and 6 allenhead cap screws. There are also rail covers included, though they can wait to be installed.

To start out with your upper, we will need to pull the flash suppressor off. It comes off counter clockwise when looking at it from the front of the weapon.

Next, we need to brace the Front Sight Base (FSB) on something solid so we can drive the pins out. I use a piece of pine, but you can use whatever you have lying around that is solid, and won’t give. Carpeting or similar soft objects won’t help out any, it needs to absorb the blow we are about to impart upon it.


With the FSB braced, we need to use our punch and SOLIDLY hit the two pins in the FSB. If you look at each side of the pin, you should see that one side is a little fatter than the other. We want to drive the pins out toward the fat side. Sharp blows from the hammer will prevent the head of the pin from mushrooming. If you hit little smacks, you aren’t going to get it free, and you will only get frustrated. The bigger hammer theory works in this regard, so don’t be using your wife or moms little tack hammer.

When we have both of the pins out, the FSB will slide away from the barrel in the same direction as the Flash Suppressor. It may be hard to get it moving, but a few whacks with a board against the back of the FSB, or use of a mallet should get it moving. If its an old weapon, and it REALLY doesn’t want to move, you can heat the FSB with a torch, freeze the entire assembly, or use some penetrating lube and let it sit over night. Any one of these tricks has worked for people.


22 June 2007, 10:42
Next we need to brace the upper receiver in our receiver blocks. There are a few different styles, and both are shown below. Either will work fine. Lock the upper in the blocks, and then clamp it in a vise. For purposes of this writing, I am not showing a vise, but I have every bit of faith that all of the readers know what a vise is, and how to use it.


With the receiver locked in place, we need to get the old Delta ring and barrel nut off. Grab your barrel nut wrench, press in directly to the rear to override the spring pressure, and turn counterclockwise (just like the flash suppressor). You may find that the barrel nut/ Delta ring assembly does not wish to come off. If this is the case, grab a cheater bar and increase your leverage. Some of these can be very tight, while others are pretty loose.


With a little effort, and possibly some harsh language, it will come off and look like the below picture.


Your upper receiver should now be apart, and look something like the below picture.


22 June 2007, 10:43
Note that the male threads on your receiver will have grease on them. Leave this on there, itís a good thing. Next, we want to position the barrel nut collar with the cup end facing away from the receiver. It should look like the below picture.

With the collar in place, now we want to thread the barrel nut over it. If you look at the below picture, you can see that there is a hole for the gas tube to line up. The collar will spin freely until everything is tightened down, which makes the gas tube installation a nice and easy task. For now, get it hand tight, and then look for your DD barrel nut wrench, we will need it in the next step.


Now we will need to tighten down the barrel nut (50ft lbs). Remember that the barrel nut collar will still spin, and that this is part of the design.


Now lets slide the rail on. If you are using a flattop upper receiver, you can use a carry handle to bridge the upper receiver and rail, to align everything perfectly. If you donít have a carry handle, its possible to do by hand, but a little more care needs to be take when installing the screws.


We will now tighten down the screws. Before we do this, we will want to make sure that the gas tube hole is lined up. Once you have done that, thread the screws in hand tight. The top and middle sets of screws are installed from the rear of the weapon, while the bottom screws install from the front.

With the screws hand tight, we now want to start using the allen wrench to get them snug. Donít just crank down on them, remember that we want to install these the same way we would put on lug nuts, which is tighten them a little at a time, and from opposite sides. Overall torque specs call for 30 inch lbs on the set screws.


With the rail firmly in place, now we can reinstall the Front Sight Base and gas tube. Run the gas tube down through the rail, and look from inside the receiver to see the gas tube. Press it through, and if needed, tap the FSB into place. You should see the holes line up for the FSB pins.


Press your FSB pins back into place (from the same side they came out), and then firmly tap them back into position with your punch and hammer. I usually use the same piece of wood to brace the FSB for this part as well. After the pins are in place, the flash suppressor goes back on. If your FS uses a washer, make sure you donít forget to put that back on also.


22 June 2007, 10:43
OUSTANDING!! You should now be ready to reassemble your upper receiver with your Bolt Carrier Group and Charging Handle. Optics, lights, lasers, and vertical foregrips are all ready for mounting.

The below pictures donít show the rail covers that come with all Daniel Defense rails, but they are worth putting on to protect your investment. Please remember that because you have pulled the barrel, you will need to rezero your weapon. I donít mean to be insulting by bringing that up, but some people tend to forget.

Here are a few pictures of the weapon we just dropped our DD 7.0 Lite on.