C4 Rail, Mid Length Cutout Rail Handguard

Usually Ships in 2 to 3 Business Days - Custom Cerakote Lead Times Vary (See Disclaimer Below)
(3 reviews) Write a Review


The Centurion patented C4 rail system is a lightweight, rugged, 2 piece free float rail that when installed gives the uppers a continuous 12o'clock rail. The C4 system is the lightest and most rigid rail that clamps to a standard barrel nut on all AR15, M4, and M16 type weapons systems. This design allows the installation of the rail on an upper assembly without removing the front sight post or permanently attached muzzle devices. **Some FSBs may need to be modified to fit by filing down the longer sling attachment ears so that they are not touching the handguard**

**Current version of the rail has some slight cosmetic differences from stock photos
Engraving is now machine engraved and black anodized....no white markings.

*** We recommend gunsmith installation for all of our parts.  We cannot warranty items damaged by improper installation.



Material: 6061 T6

Finish: : type 3 hard coat anodized

Weight: 12.4oz with screws---1.1oz with standard barrel nut

Length: Top 9 1/4in Sides 11 1/2in Bottom 10 5/8in

Width: 2.1in

Height: 2.38

Inside diameter: 1.37

Rails: 1913 spec rail

Fasteners: grade 8 bolts phosphate finished


***Please Note***

- Screws are included with the purchase of all rail systems and replacement screws are available to purchase if necessary

- Hex wrenches/keys are not included but installation will require 9/64" and 3/32" SAE Hex Keys


Custom Cerakote Disclaimer:

Custom Cerakote is completed per order.  Our Cerakote room runs one color at a time so your ship date will be subject to the color rotaion at the time the order is placed.  You will receive an email confirmation once the item has actually been packaged to ship.

Cerakote items are not guaranteed to match separate batches or Cerakote completed by outside parties.  While we strive to keep our mix uniformed for our own products, we can't say for certain what Walter and Jesse cooked up in their lab out in Albuquerque.

ONE YEAR LIMITED WARRANTY Centurion Arms warrants the initial retail purchaser that all Centurion Products will be free of defects in workmanship and material for a period of one year from the date of purchase. Centurion Arms will replace any part found to be defective. Centurion Arms is not responsible for any damaged products caused by improper installation or improper installation procedures. All Centurion Arms products should be installed by a properly trained gunsmith or armorer. Centurion Arms designs products around US Mil Spec components and there may be some components out there that do not conform. Centurion Arms will not warrant any product that has been altered or modified by the customer in any way. Centurion Arms does not recommend installation of C4 rail on barrels with pinned/welded muzzle devices and does NOT warrant labor with regards to removing pinned and welded muzzle devices That is to be worked out by the end user and the installer.


  • 5
    My new favorite set up

    Bought this for a pinned and welded 14.5 mid length fixed sight post build I was doing and it was above and beyond what I was looking for. Mounts securely and easily, not too heavy, the sling mounts are solid and there is very minimal flex when locked into the sling in a rifle position. Not cheep but well worth the price. Top notch quality!

  • 5
    Centurion C4 midlength cutout

    This rail is the best quad rail I have ever used. Lightweight, locks up tight, precisely machined. It feels indestructible. This rail brought me back to quad rails from the Keymod/MLOK dark side. My favorite rail by far, saving up for another.

  • 5
    Cmr middy cutout

    Got this secondhand and am in process of saving for a comolete 12,5 with fsp and this rail. It is on my short list of factory rifles.
    Now, on to the rail. Its incredible. I honestly dont know how dd got their risII accepted instead of this... Its lighter, better, more appealing anf appears stronger!
    Bottom line? Get it.