Running the Centurion Arms CMR rail is quite a reversal for me. I’ve run quad rails since my first DPMS rifle was modified at a gun store in Garland, Texas, long before there was a SHWAT™ website. Even before I’d shot my first hog. Fast forward, I’ve used plenty of quad rails, most recently a C4 rail from Centurion Arms. I’m seriously all about choices, and a quad rail makes it easy to change configurations on the fly, thus my hesitation to go to a modular rail. I’d used a tube rail on 6.8 AR in the last year or so, and it turned my head. Still, it wasn’t nearly as stiff as a quad rail, and it lacked any easy configuration options. So with an open mind, and maybe a hint of trepidation, I went searching for a tube style rail that was strong and would give me mounting options for the smorgasbord of accessories I have in spades. Not that I think I need to use them all at once anymore…
Most of us would probably agree that form should follow function. Most of us would also agree that on our personal rifles, the form should be nothing short of total awesomeness. So let’s get that out of the way here first. The Centurion CMR is a great looking rail! In a perfect world, form and function leverage each other like the down force created by a Ferrari’s fantastic lines. Okay, the rail isn’t a Ferrari, but on the CMR Centurion seems to have gotten the form and function equation figured out. For example, check out how the four QD sling mounts are smoothly integrated into the rail.
My CMR is the 14” .556 version. Naked, the rail lines are smooth and the feel is great. If this were a handgun review, we might say it was “dehorned.” That has a lot to do with the end price. I’m no machinist, but it’s not too hard to figure out that it takes work to smooth out the edges, and work that requires time and tools. Here’s what really stands out to me – the picatinny rail. The one place on this rail that would seem to be the most likely to have a sharp edge, or dozens of them, is clean just like the rest of the rail. I can literally squeeze the picatinny rail between my thumb and forefinger, then run them down the length of it without a hint of discomfort. That’s some serious attention to detail, proof of quality workmanship.
The proof is apparent all along the smooth lines of the 1.56 inch diameter tube body. I generally wear a small or medium glove, and that tube size hits a sweet spot with me. If this rail were simply mounted to a range toy, or maybe if I always wore gloves when shooting and hunting, I’d be good to go at this point. However, neither of those things is true. When shooting or training, rails can get hot. When hunting, things can get slippery when wet. For that matter, it get’s hot here in Texas, and sweaty hands can be an annoyance when running your gun.
Happily, Centurion created rail covers that strike a terrific balance. The direct mount rail covers perfectly wrap the diameter of the tube. Use a few in key positions, or cover up the rail to your heart’s content. These things look great in pictures, and looking at the images you might conclude they are quite rough on the hands. But when you handle these, you’ll probably be surprised. Stippling on steroids, yes. But they still have no sharp edges.
The CMR rail covers are proprietary, and this caused some initial hesitation on my part. But having jumped in with both feet, I just haven’t found a downside yet. The rail covers are just part of the equation. You can add a picatinny rail section or sections where needed. I added one out front at six o’clock to mount my bipod before zeroing. Rock solid. If you are a Surefire Scout light user (and I’m not), you’ll love the CMR mounts for the M300/M600 series. Any lower profile, and the light would integral to rail itself. I’m currently experimenting with the CMR handstop.
Remember, these are all proprietary mounts. You know what the best part of this mounting system is? No backing plates! I have a short tube rail on a pistol build, and the value of simply screwing down the rail cover or other mount without have to jack with backers for the screws is incontrovertible.
When it comes to mounting the rail on your AR-15, it’s the same deal. Simple. Centurion supplies the barrel nut. You’ll need a single tooth barrel nut wrench or some substitute to tighten it. Slide the CMR rail over the nut, push the rail into position, tighten three screws. Boringly simple. Spectacularly stable.
Per the unwritten code of gear reviews, you might imagine that I need to find fault with something about this rail. After all, I’ve been more critical of items some of our valued sponsors have created. But so far, the CMR rail hasn’t opened that door. Maybe there’s some mount they should be making. Maybe Centurion is missing the boat by not having a vertical grip for the CMR direct mount as of this writing. But at this moment, I don’t really care. Multiple vertical grips are in a bag in the next room and I have CMR rail sections. If I want the vertical grip, I’m already good to go. Where’s the downside to that? You be judge – order one and see for yourself.
Material: 6061 T6
Finish: : type 3 hard coat anodized
Weight: 12in-10.7oz 14in-11.6oz with barrel nut and hardware
Length:12.56 (12in) 13.688(14in)
Width: 1.56(body of tube) 1.75 (at QD sling swivels)
Inside diameter: 1.12
Rails: 1913 spec rail on top
Fasteners: grade 8 bolts, phosphate finished