Knights Armament Company (KAC) M4 RAS for M4 Carbines (#98064)

MSRP: $295.50
Your Price: $280.73
(You save $14.77 )
Machined from aircraft grade aluminum
Stock Status:

Out of stock

M4 RAS Forend Assembly


The KAC M4 RAS (Rail Adapter System) was developed for use on the US military’s M4 Carbine, and with over 1 million rails issued to date, it is one of the most battle proven designs available for the AR-15 platform. This non-free float handguard is a simple-to-install, drop-in upgrade that features genuine Mil-Spec M1913 Picatinny Rails along its entire length. What sets the M4 RAS apart from other 2-piece quad rails on the market is that it securely locks to the rifle’s barrel nut via a clamp and screw arrangement, making it a very solid foundation upon which to mount tactical accessories. Includes three KAC 11 Rib Rail Panels.

Rifle Requirements: The M4 RAS is a drop-in replacement part for standard, 2-piece polymer, M4-type handguards. The rifle must have a carbine length gas system, delta ring assembly, fixed front sight/gas block, and round handguard end cap. Lighter barrel profiles work best (M4 or Government contours). Heavier barrel contours may require modification to the inside of the rail. For AR-15/SR-15 based platforms only; not compatible with SR-25 variants. Installation instructions are included.   


Weight: 8.9oz

Length: 6.25″

Free Float: No

Material: Aluminum

Finish: Black Anodizing

***This product contains chemicals/materials known to the State of California to cause cancer and other reproductive harm. To learn more, visit***

3 Reviews

  • 5
    top notch rail

    I like the way it locks in, steady will not move. I can tell it can take the abuse..rock solid.. It worked perfect with my Colt Heavy barrel...did not have to modify it if you have a Colt Heavy barrel it will work.

  • 5
    Best in Slot

    If you're looking at this it's because you know it's the best drop-in carbine quad rail ever made, so if you're reading the reviews it's only for to verify it's the right part for your USMC clone, and it is the right part so go ahead and add to cart. Bravo Company is an awesome company and the price was spot on, had mine on my rifle 3 days after I clicked the buy button. Why on earth are you still reading my crappy review??? Buy it already.

  • 3
    Heavy and Uncomfortable

    Used this rail in the Army. It's pretty heavy for what it is, never realized just how bad until I handled a friends civilian M4-clone with a Larue rail installed. Also it's very uncomfortable, the KAC rail covers are terrrible. I'm giving it 3 stars because it still does it's basic job: it is a quad rail. Also it's relatively easy to remove for cleaning.