Forward Controls Design RHF4 Picatinny Handguard – 11.5″


Flat Dark Earth (FDE)

Product Description

From the Manufacturer:

We have long been fans of the classic KAC RAS since the early 2000s. Throughout the years, we’ve seen trends for lighter, small diameter, and rails-only-where-you-want-them handguards, this was before the advent of Keymod and MLOK. Then quad rail made a comeback. We don’t follow trends for many reasons, chief among them is practical designs aren’t subject to ever changing fads that are quite aimless in our opinion, practical and durable designs are always useful, regardless of which way the wind blows.

We’ve stayed with handguards with 1913 rails in four-quadrant for their versatility, and we weren’t concerned with the then-popular, now less popular ways of using the support hand to grasping the handguard, which called for their being of smaller diameter. Quad rails still offer the most versatility and rigid means of attaching Picatinny-based accessories.

While we do offer MLOK handguards (RHF, with 1913 rails on top, and MLOK at 3, 6, and 9 o’clock), a quad rail handguard is what we’ve always wanted.

RHF4 comes in two lengths, 11.5″ and 9.5″, it is a quad rail handguard based on the successful Centurion Arms C4 rail system. It is a lightweight, rugged, 2-piece free float rail that provides a continuous 12 o’clock rail when installed on the upper receiver. Like the C4 system, RHF4 is a 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.

RHF4 incorporates Forward Controls design input: Omission of built-in QD swivel attachment points. Some like the now common front and rear located QD sockets, we prefer the location of the front sling attachment be left to individual users. A QD swivel can be ordered with RHF4 as an option. The rail numbers are machine engraved, and a subdued Cygnus is engraved on the right side of the RHF4.

RHF4 has KAC rail panel clip cutouts in front and back.


  • Material: 6061 T6
  • Finish: Type 3 hard coat anodized
  • Weight: 12.40 with screws—1.1oz more with standard barrel nut
  • Length: 11.5″
  • Width: 2.1in
  • Height: 2.38
  • Inside diameter: 1.37
  • Rails: 1913 spec rail
  • Fasteners: grade 8 bolts phosphate finished

RHF4 installation directions can be found here (a hard copy is included with RHF4).

NOTE 1: RHF4 is not compatible with BCM’s Mk2 upper receivers without modification to the RHF4’s anti-rotation tabs, or to the upper receiver itself.

NOTE 2: RHF4 is not compatible with the A2 FSP without modification.




Technical Information

Firearm Compatibility





Mounting Platform



Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit

Customer Reviews

Based on 4 reviews
Jeremy C.
Fcd rhf4

No frills quad rail!! Everything you expect from fcd. Solid build and great looks highly recommend there products. Milspec also is one of my go to's for parts. Great service,prices and free fast shipping!

Better than the RHF-C-11.5

Overall happy with the rail, fit and finish are typical centurion arms. Product was not T Marked like stock photo which is my only gripe. Rails were in spec and matched up perfectly with my Colt and BCM uppers


No review needed

Michael C.

Package came fast , rail came in perfect condition, and fit and finish was flawless. Highly recommended FCD products and doing business with milspec retail again. This was my first purchase from them and I was so pleased I ordered several more parts from them already and was just as pleased with my second transaction. Buy with confidence, I highly recommend this product and doing business with milspec retail. Thanks milspec your products , prices , and service is exceptional.