Daniel Defense RIS II Installation Guide

[Fluffy Boy 32]

Recently posted this on my blog and I thought it was worth a share on the forums. Enjoy!

Lately I've gotten a few questions about the installation process for the Daniel Defense MK18/M4A1 RIS II so I thought I'd make a guide for anyone that wanted to know how to install the rail.

Things you will need for this installation:
(1) One Size 5/32 Allen Key
(1) One Size 3 Allen Key
*Optional but highly recommended*
(1) One Daniel Defense Barrel Nut Wrench


First you will need to slide the locking collar all the way down to where it is flush with the upper of the gun. Make sure the two pieces on the locking collar are on either side of the body.


Now that you have the locking collar on, make sure that the barrel nut has the lip side up and slide it down the barrel onto the locking collar like so:



Make sure to torque the barrel nut down to where the locking collar has no side to side play at all or your rail system with have a lot of wobble.


Before you move to the next step, look at your locking collar and make sure that it is straight and flush with the upper receiver. If the locking collar is not flush, it will cause the rail to be crooked when you are finished. To correct this, simply loosen the barrel nut and adjust the locking collar to the correct position.

At this point, you can go ahead and install your gas tube/gas block if needed. If not, proceed to the next step.

If you've tightened down the barrel nut as much as you possibly can and you still have some side to side play on the locking collar, try slipping an o-ring down between the barrel nut and locking collar. This will close the gap between the two and keep the collar from moving. Use a small screw driver to slowly push the o-ring over the threads of the barrel instead of trying to use the barrel nut to force it down into the gap.


Now that you have the barrel nut and locking collar in place, go ahead and slide the rail system down the barrel and line up the screw holes. If you haven't already, go ahead and separate the lower rail from the rail system which will allow you to screw in the two bottom screws. Make sure that you have all your screws going in the right direction for the best fit.

Using the 5/32 Allen Key, go ahead and screw the (6) six screws in like so:


Once you have all the screws in place, go ahead and install the lower rail.


Make sure that the tabs on the lower rail and the cut outs on the rail system line up or the bottom rail won't be able to install. It's almost fool proof but just in case you missed it, here you go...



Using the #3 Allen Key, install the (6) six screws on both the left and right side of the rail (three screws to each side).


You're done! Here's what your final product should look like:




I hope this guide helped some of you that were having problems with installation or just wanted to see what the installation process is like. I would highly recommend picking this rail up if you're wanting to change up the look of your standard AR variant!

If you're more of a video person and prefer that over standard blog style guides, I got ya covered!


Feel free to leave me feedback!
Thanks!

[trevorst]

Very nice write up, nice rail also I might add.

[vulrath]

An observation: the washers that came with your rifle to shim the delta ring will allow for a much more precise fit when shimming the barrel nut. An o-ring will still work quite well (hell, I've seen people use elastic hair bands), but I just wanted to offer this little tidbit.

Did you use a real or replica nut? Did you have to modify either?

I normally severely dislike RIS/RAS, but I found a replica DD rail, and barring my finding the actual rail I'm interested in ( I doubt I'll find it without buying a specific KA rifle) I'm actually diggin' look of the DD rail on my custom DMR build (the one that's utilizing my AABB Troy receiver). I really like the write-up; it's really helpful in helping me make up my mind.

[Fluffy Boy 32]

I don't think I could use the washers because anything thicker than the o-ring and it wouldn't fit. The o-ring barely fit...

The rail in the guide is an ACM because I didn't have enough for the Madbull/SOCOM Gear version along with the Madbull G&P threaded Barrel Nut.
I had to replace the AEG barrel nut that was supplied with the rail with a Madbull G&P threaded barrel nut. I had to use the o-ring to fill the gap that the other barrel nut would've filled. If you have the licensed Madbull Rail, it will fit nice and snug.
I haven't had any problems with the rail so far. I have noticed it scratches easily but that could just be because I'm OCD about everything and the smallest things I notice. I did notice when I did some photo comparisons between this rail and the Madbull version that the two tabs needed to free float a M203 are missing on the ACM rail. My main reason for buying this was because I just liked the look and being able to take the screws off the sides and have the lower rail drop down so I can adjust the hop up was another plus.

If you want the ACM rail, I can get you in contact with the guy I purchased mine through but I would highly recommend the Madbull version if you are willing to pay the extra.