Expo Arms M4 RAS Quad Rail Handguard - Carbine Length
At first look, this Rail Adaptor System appears to be a direct copy of the KAC model used on the military M4, and its been in use for a mighty long time. Credit for this review should go to
richiecotite who pointed it out in another thread. I purchased this rail direct from Primary Arms and the price at that time was $111.99, and by the time it made its way to the Stick compound the additional shipping and taxes bumped it to $126.92. Many of the items I review are comped, and are later given away to MIL and LEO who can not afford to buy similar items due to their lack of funding. I do NOT make it a point to write negative reviews, and I have stated this multiple times. If an item isn't worth my time, I'm not going to shoot pictures and write about an item based on my training and experience (which equals money) when I could be doing something else I enjoy or makes me money. That is just how I roll, though it is something which offends a few people on the internet.
The original KAC rail was solicited by the US Armed Forces under contract DAAE20-97-D-0020 in 1997, and by 1999 KAC had shipped 1,000,000 rails to the military. This impressive feat shows not only the design and manufacturing capabilities, it also shows the staggering clout that KAC brings to the military market. There are multiple clauses in the copyright world, and I am by no means an expert or lawyer, but the magic "25" years is common for holding a copyright for certain things, and the KAC RAS appears to be one of them. We have seen KAC appear to lose the RAS contract to P&S (whose name has changed at least once), and it appears Expo Arms is also now in the RAS market. While it is conjecture on my part, it appears Expo Arms is an offshoot or sister company to Primary Arms. Instead of branding RAS as Primary Arms, and only being sold by them, the Expo Arms company can shop them around to any of the various AR15 parts or MFG companies, and as of this writing it looks that Brownells (AR15.com owner) is also selling them.
The KAC RAS rail was designed to attach various items to military weapons in a secure and solid manner. I will not get into the debate of who created the 1913 rail interface. Whether you believe it is KAC, ARMs, or that it came from Picatinny Arsenal design teams really doesn't matter at this point. We all know it, and all use it. While MLOK, direct mount, and Keymod have all come to the market since the advent of the 1913 rails, the fact of the matter is that the 1913 spec is still in use on most barrel covering devices (even if only on the top). We can be pretty clear in seeing that 1913 isn't going anywhere for quite awhile.
Upon the drop off from UPS, our package was delivered in good shape, with the rail wrapped in two layers of plastic, shrouded in brown paper. The packaging was more than sufficient. There were no instructions inside, there was nothing stating what it was, it was simply the RAS with the two halves together and the ribbed covers in place.
Popping the rails apart and examining the inside, the heat shields are sturdy and unmarked with anything other than the "Forward" stamping/ engraving. The upper rail shows no obvious shortcuts, and the two metal ends for aiding in attachment are in order. Nothing out of the ordinary here, and again, it all looks well machined inside.
Taking the rail covers off gives us a clearer view of what we are looking at. The first thing that stood out to my eye was that the anodizing was fantastic. It is a deep clean black, with no hints of purple, blue, or contaminates. If you are seeing any color shifts on the display you are looking at, it could be your monitor or viewing device, or it could be the quick processing and resizing slapped on these images, but in person the color and depth of anodizing looks fantastic. If the Expo Arms guys read this, send my thanks to whomever does your ano work, because they did a great job.
Next we look at the size, depth, and cleanliness of the machining. The 1913 rails all look in good order and even. To my eye, the machine work is rock solid. There are no chatter marks, which are most commonly found when a machine is cutting a bit too quickly for the given material. There are no evident tool marks. The deburring work is very well done, which leaves the 1913 sections sharp and clean. When I say "sharp", I DO NOT mean sharp as in it will cut. I mean the edges are clean without being rounded over. The edges are not like cheese grater, they are square and it is clear the machine work was not done with dull bits or rushed along.
Holes and mounting barrel nut support are clean and positioned appropriately. There was nothing out of place or botched that I could determine.
This image shows the section which mounts in the handguard cap. It is as straight forward as you expect. This should not be a shock by this point, but I'll point out that this is not a newly conceived rail, this is a rail which has been produced in the millions with any issues having been taken care of decades ago. Unless you need KAC engraving, this is functionally the same RAS from what I can tell.
Here we see the end which locks into the barrel nut and delta ring assembly. Again, it is on target for how it should look, all the way down to the darkened screw head. Dust or lint in the pic is from my own place, no extra charge for the viewing...
If there is complaint from the cloners, it is probably going to come from the lack of marking on the rail covers. However, the rail covers have nice tight locking tabs, which are blackened and secure well into the RAS when slid into the correct locking slot. Much like the rest of the pieces, these rail covers make do with the simple 8FW25 marking. The covers appear to be a similar material, and have a similar texture on the outside to the original covers. They are not shiny, or glossy and do not look like some of the airsoft knockoffs. These covers will no doubt function fine, though I will say I have not fired this weapon with these rail covers. If the covers get hot and soggy, I'll update this to reflect that issue, but at this point it does not seem likely.
Installation of the rail is straight forward, and this is not an installation article. Angle the front of the top rail and put the metal tab under the handguard cap. Loosen the screw up top and pop the top rail into place like a handguard. I undid the screw all the way, then tighten it a little once the rail was in place. The lower rail slides under the handguard cap as well, and by pulling down on the delta ring, the lower will pop in. Then make sure your top screw is tight. Again, that is a brief overview. Actual assembly and instruction is available from military manuals and videos if you don't know what you are doing.
To sum things up, the Expo Arms M4 RAS rail is a well designed (thank you Mr Knight), well manufactured (thank you EA) rail, and an almost dead on clone for the rail made famous in the Global War On Terror (GWOT). CNC work on the rail is very clean, assembly is easy, anodizing is outstanding, and the included rail covers are as functional as they were in design 27 or so years ago. If you understand that this rail is not a free float rail, and shouldn't have lasers or optics mounted to it (though some people do without complaint), you will most likely find this to be a fantastic rail at a wonderful price. KAC lists this rail as out of stock and I don't think its been made in while, but it last was listed at $295. If this rail doesn't get crazy priced, and stays under $150 in today's dollars, I think its a steal.
The below image shows the complete weapon, but I'm going to assume most people are familiar with military M4s and know what they look like. The below AR15 is a retired Police carbine that was used for illustration purposes.
Questions or comments? Fire away!
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Originally Posted by Wake27
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