DD 12" Lite rail vs DD RIS II BLACK 12" rail

[GUNSLINGER733]

My main concern is I have a 3 week old dd 12" lite rail and I'm wanting to swap to a ris II(black version). I'm running a 14.5" mid gas system with low profile gas block and concerned if I'll run into any problems using this rail on a middy. I've read some have and some haven't. If someone knows please chime in. Thanks

[GUNSLINGER733]

Btw the only reason I'm wanting to swap is the height of rail bothers me somewhat. Other than that it's a badass rail.

[bp7178]

The 12" DD RIS-II will work perfectly with a mid-length. This rail is also sometimes called the M4 RIS-II. The shorter version is sometimes called the MK18 RIS-II.

There was some speculation that the MK18 RIS-II wouldn't work on a mid-length. The MK18 is shorter at about 9.55". I've seen a few pics of the MK18 on mid-length gassed barrels, and while the gas block sticks out, it seems to work.

[TehLlama]

As long as the gas block isn't oddly large, or a cut down unit done poorly, you're fine.

[GUNSLINGER733]

Alright that's what I thought. Thanks guys and I also have a low pro gas block so that shouldn't be a issue.

[wild_wild_wes]

The M4 RIS-II is heavier than the DD Lite 12, isn't it?

[Col_Crocs]

Yup, the RISII is a bit heavier.
If your gasblock clears the Lite, it will easily clear the RIS.
OP, not sure what your plans are but incase you plan on simply unbolting and swapping out rails, the bolt up collars on the RISII and Lite, while similar looking, are supposedly dimensionally different.--The Lite's being narrower due to the rail's slimmer profile. I cannot confirm this myself since I do not own a Lite but this was discussed here a while back.

[ArmySGTPM]

I realize this thread is a bit old...but I can't seem to find the answer to this life long questions haha


how tall is the ris II? I have a DD lite rail and I do like it, the height is a bit tall though...on my new gun i'm looking at the Mk-18 RIS II and i just wanted to know the actually height....no one seems to have it listed anywhere...

a comparison between the lite would be even better :D

[Stickman]

That is because this thread is about using a midlength gas system with the RIS II M4A1 rail. The rail includes hangers for the M203 which block the midlength gas block and prevent installation. Thankfully, the cure is simple as an allen head wrench takes the hangers out freeing up the needed space.

There is a diagram which shows the info you are looking for, if you check around you should be able to find it. I don't upload images that aren't mine, so I don't have it off hand.

[bp7178]

http://i37.tinypic.com/2f06atc.gif

[ArmySGTPM]

http://i37.tinypic.com/2f06atc.gif

wow that is a great comparison!