View Full Version : Daniel Defense RIS II - A Brief History

25 January 2008, 22:01
The SOCOM RIS II rail contract provided all current and upcoming weapon and accessory manufacturers with an opportunity to demonstrate outside the box development, and enter into trials for the (at that time) upcoming rail selection.

ARMS, KAC, and DD all advanced past initial testing with high quality rail systems which humbled their competitors. Regardless of the outcome, all three had shown that they were solid performers. Of course in the end, the selection was narrowed to one, with Daniel Defense being awarded the contract and becoming the sole source supplier for SOCOM.

Below reads the Daniel Defense description for the DD RIS II rail, but the end product isn't how it started out, nor it is likely to be the final product either.

The Daniel Defense RIS II allows the individual operator to free float the M203 grenade launcher without additional parts. As importantly, special tools are not required to mount the M203 grenade launcher. This was accomplished by integrating all of the needed parts to free float the M203 into the rail itself.

The Daniel Defense RIS II free-floating Picatinny rail systems are designed to allow individual operator to quickly, and without special tools, mount M203 Grenade Launcher and precisely mount SOPMOD accessories to host weapon without effecting point of impact.

The original DD RIS II extended past the standard FSB through the use of a cutout in the upper rail. It also used 2 machined screws to lock the lower portion in place. Once the screws were removed, the rail pulls down from the front, then out. In the below picture you can see the 203 mounts that swing down.




25 January 2008, 22:01
Here is a picture showing the early DD RIS II on a military upper, with the M203 installed.


25 January 2008, 22:02
Daniel Defense was awarded the RIS II contract, and several changes were made to the rail system. The most obvious was losing the Front Sight Base (FSB), and going with a low profile gas block. This increased usable space on the upper rail, as well as extended the sight radius.

The DD RIS II A2 rail was originally designed as a rail for the M16A4, but found itself equally at home on a carbine. Pictured below are a few of the configurations that I ran the upper on. Its worth pointing out that the barrel shown below is on a prototype melonite barrel that is 16", and not the military carbine length of 14.5".



Below the upper is shown with some other prototype equipment, and is being worked with a MIL team on a M4 carbine lower.

27 January 2008, 10:28
Included in the modifications was removal of the external head screws, with those being swapped out for flat head screws which are flush with the rail. This allows for mounting of lights or other items directly over the screws. More obvious was the removal of the standard FSB, which is the design that finalized the rail. To the best of my knowledge, this was the first time that the US Military has utilized the M4/ M16 weapon system with an extended rail and folding sight.

The below pictures show the currently issued DD RIS II rail on a Colt 6721 lower (PRI sights are not issued items).



27 January 2008, 12:24
Installation of the DD RIS II rails is pretty straight forward, and the Guide to installing DD Lite rails can be used for complete information as they install in the same manner. Removal of the Front Sight Base (FSB) and barrel nut/ Delta ring is required off the host weapon, and a low profile gas block is used to replace the FSB.

DD Lite Rail Installation Guide (http://www.weaponevolution.com/forum/showthread.php?t=1)

Shown below are the rail, barrel nut, locking collar, and 6 screws.


31 January 2008, 16:20
The DD RIS II has spun off additional rails at the request of SOCOM, with the most well known being the MK18 rail.

I will update this thread with pictures and additional information after SHOT 08, when there may be something new to announce.


3 March 2008, 10:03
SHOT 08 revealed Daniel Defense had a third rail in their military RIS II series. The designation is GL/ SSC, and is designed for 12.5" barreled weapons.

GL/ SSC= Grenade Launcher/ Sound Suppressor Compatible

Shown below is the three RIS units all together.


20 December 2008, 15:00
Daniel Defense M4A1 RIS II FSP

At the request of military units, a new Daniel Defense RIS II rail was designed and manufactured. This rail appears to go back to the roots of the initial DD RIS II rail that was entered into the early rail trials. The Front Sight Base (FSB) passes through a slot in the top rail. This permits continued use of the standard FSB, along with the enhanced strength that the a pinned gas block brings. The should allow for armorer level installation for many Law Enforcement and MIL organizations.

Unlike its prototype sibling, this does not have screw heads which protrude from the rail sides. The bottom rail is still removable for grenade launcher attachment, but a flat head screwdriver will need to be used to remove the four screws. Once this is done, the bottom sections pulls away, and the grenade launcher mounting points swing down for easy access.

While shown below with black type III anodizing, the Daniel Defense M4A1 RIS II FSP is also available in the SOCOM specified FDE type III anodizing as well.