C4 Rail (7in - 12in)

Usually Ships in 2 to 3 Business Days - Custom Cerakote Lead Times Vary (See Disclaimer Below)
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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.


7 inch
Weight: 8.7oz with screws---1.1oz with standard barrel nut

Length: 7.3in

Width: 2.1in

Height: 2.38

Inside diameter: 1.37

9 inch
Weight: 10.6oz with screws---1.1oz with standard barrel nut

Length: 9.25" in

Width: 2.1in

Height: 2.38

Inside diameter: 1.37

10 inch
Weight: 10.7oz with screws---1.1oz with standard barrel nut

Length: 10in

Width: 2.1in

Height: 2.38

Inside diameter: 1.37

12 inch
Weight: 14.2oz with screws---1.1oz with standard barrel nut

Length: 12.565in

Width: 2.1in

Height: 2.38

Inside diameter: 1.37

***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


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


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 rotation 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.
6061 T6
Type 3 Hard Coat Anodized
1913 Spec Rail
Grade 8 Bolts Phosphate Finished


  • 5
    C4 12in

    It is great except for a gapped milling cut at the base.

  • 5

    Centurion rails are absolute top notch. Great fit and finish. Worked great for my MK12 build.

  • 5
    12-Inch C4 Rail

    MK12 Perfection!!! Got rid of my M-LOK Rail and swapped for this 12" C4... Sooo very glad I did. Not only looks appropriate, but is even more functional than my previous.

    You cannot miss with Centurion Arms products!