* RHF4 isn't compatible with the A2 FSP without modification.
* 2021 production RHF4 does not have the 1913 rail numbers (T marks).
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 hand guards, 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 change 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 hand guards 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 hand guard, 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 hand guards (RHF, with 1913 rails on top, and MLOK at 3, 6, and 9 o'clock), a quad rail hand guard is what we've always wanted.
RHF4 comes in two lengths, 11.5" and 9.5", it is a quad rail hand guard based on the successful Centurion Arms C4 rail system. It is a lightweight, rugged, 2 piece
free float rail that provides a continuous
12o’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
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.
RHF4 does not come with the TDP barrel nut, but can be added as an option.
• Material: 6061 T6
• Finish: : type 3 hard coat anodized
• Weight: RHF4 11.5: 12.4oz with screws---1.1oz with standard barrel nut. RHF4 9.5: 10.5oz with screws---1.1oz more with standard barrel nut
• Length: RHF4 11.5: Top and sides: 11 1/2in. Bottom: 10 5/8in. RHF4 9.5: top 9.5 in Sides 9.5 in Bottom 8 in
• Width: 2.1in
• Height: 2.38
• Inside diameter: 1.37
• Rails: 1913 spec rail
• Fasteners: grade 8 bolts phosphate finished
• MADE IN USA
• Rails: 1913 spec rail
RHF4 installation directions can be found here (a hard copy is included with RHF4).
NOTE: RHF4 is incompatible with BCM's Mk2
upper receivers without modification to the RHF4's anti-rotation tabs, or
to the upper receiver itself.
The scoffed up area is where RHF4's anti-rotation tabs need to flank.