View Full Version : Fortis REV™ Rail Installation

9 May 2013, 01:50
The Fortis REV™ Free Floating Rail System (http://fortismfg.com/index.php?route=product/category&path=59) has been out for awhile now, and has quickly become a popular, hard to find in-stock rail. For those that are interested but aren't sure if it's an easy install, and those who want some high quality pictures to look at for an existing install, read further. Special thanks to Stickman (https://www.facebook.com/Stickgunner) for the photos.

First from the Rainier Arms (http://www.rainierarms.com/?page=shop/detail&product_id=3555) website:


Fortis REV™ is an extremely lightweight yet robust free floating rail system. When designing the REV™, we didn't want just another rail system, we wanted a better, lighter, feature rich handguard that was robust and within budget. We've managed to reduce as much weight as possible while maintaining strength by utilizing a 1 piece body design. Key Mods were added at the 6 & 9 O'clock positions for modularity and additional weight savings. It's unique mounting system captures a standard AR15 barrel nut for easy installation. Check out all the features and see for yourself why the Fortis REV™ beats the competition.


◾Material: Aircraft Grade 6061-T6 Aluminum
◾Finish: Military Specification Type III Hard Coat Anodized
◾Length: 14"
◾Weight 11.0 Ounces
◾Inside Diameter: 1.340"
◾Contiguous Top Rail
◾Rotation Limited QD Sockets
◾KEYMOD at the 3 & 9 O'clock
◾Anti-Rotation Tabs (Fits Forged Uppers)
◾Uses Standard AR15 Barrel Nut (Not Included)
◾Made in the USA!

For this install, you will need an Allen Head Key set for the rail. You will also need your standard armorer's tools if you have to take apart an existing rail setup or building an upper from scratch. Armorer's wrench and Torque Wrench.

First we'll take apart the lower portion of the rail that is secured with 4 allen head screws.

http://i1016.photobucket.com/albums/af282/richdkim77/Fortis3_zpsd13677a3.jpg (http://s1016.photobucket.com/user/richdkim77/media/Fortis3_zpsd13677a3.jpg.html)

For this install, we have a 14.5 BCM Midlength upper (http://www.rainierarms.com/?page=shop/detail&product_id=3642). The Surefire MB556K (http://www.rainierarms.com/?page=shop/browse) is pinned and welded on. A BCM low profile gas tube is also installed. Normally, it would be impossible to install most kinds of rails on this upper unless the muzzle device was drilled and removed. Luckily, we had already removed and cut off the delta ring assembly. We are just left with the standard AR barrel nut. If you have a proprietary barrel nut from a previous rail install, such as from Daniel Defense, Troy, or Seekins to name a few, then you will have to take the usual steps to remove the muzzle device, gas block/front sight post and the proprietary barrel nut. If you don't know how to do this, don't fret, we are currently working on a guide for that.

http://i1016.photobucket.com/albums/af282/richdkim77/Fortis4_zps7c7dcc4d.jpg (http://s1016.photobucket.com/user/richdkim77/media/Fortis4_zps7c7dcc4d.jpg.html)

Since the Fortis rail is essentially a one piece design, we are able to install it over the barrel without removing the low profile gas block or the muzzle device. Again, this is important for this particular install, as we would have had to destroy the Surefire MB556K to install other rails with proprietary barrel nuts. Once the rail slides over the assembly, it secures onto the barrel nut, as a groove channel is cut into the rail.

http://i1016.photobucket.com/albums/af282/richdkim77/Fortis2_zpscdb4a103.jpg (http://s1016.photobucket.com/user/richdkim77/media/Fortis2_zpscdb4a103.jpg.html)

Once the top portion is secured, place the bottom piece over the lower part of the barrel nut. Once the piece is aligned with the upper portion of the rail, use an allen head wrench to secure the 4 bolts.

http://i1016.photobucket.com/albums/af282/richdkim77/Fortis6_zpsc7644c0a.jpg (http://s1016.photobucket.com/user/richdkim77/media/Fortis6_zpsc7644c0a.jpg.html)

Check your installation, to ensure that the barrel nut teeth are in the channel and the rail is aligned with the upper.

http://i1016.photobucket.com/albums/af282/richdkim77/Fortis5_zps9ebff8a3.jpg (http://s1016.photobucket.com/user/richdkim77/media/Fortis5_zps9ebff8a3.jpg.html)

Now you are finished.

http://i1016.photobucket.com/albums/af282/richdkim77/Fortis1_zpse650d04c.jpg (http://s1016.photobucket.com/user/richdkim77/media/Fortis1_zpse650d04c.jpg.html)