New Rail Hotness?**UPDATE post #47 w/pics

AR/M4 AR General Discussion
1

I’ve sold the Daniel Defense 14.0 Lite off my upper. Here’s how I got it:

I ordered the upper from smartgunner last year (DD factory assembled) and they were out of the Omega 12.0 I wanted at the time. I needed the upper for a Vickers class I had scheduled and so Tommy offered me this upper with the 14.0 Lite rail at no extra charge. I figured, “why not” and ran it. It’s not bad, but it’s just really long. I’ve also grown to feel that the rail is very “tall.”

When I built the gun, I was trying to mimic the feel and handling of a KAC SR-15.

So, now that the 14.0 Lite rail is sold, I’m left with deciding what rail to replace it with. The new Centurions look good, so does the DD RIS II M4A1, and it would pretty well match my MK18 too, in terms of feel, but it’s a little heavier.

The barrel is a 16" mid and I want to keep the gas block covered to protect it from impact, so I guess the MK18 RIS is as short as I could go. The shorter rail would be lighter weight. Then again, the rifle has a Nightforce 2.5-10 on it and my Larue bipod mount is supposed to be here in a few days. Wouldn’t it be advantageous to have the longer rail for bipod mounting? By the same token, though, the rifle won’t always wear the bipod, and I still want the rifle to be light and maneuverable.

As a final note, after running the Vickers class in an all-day rainstorm, I can appreciate the importance of being able to remove the bottom rail for cleaning/rust prevention instead of just spraying CLP in to the rail holes onto the barrel and hoping for the best.

So, which rail and why? I don’t like the Troy/VTAC tubes, so those are out.

DD MK18 RIS II
DD M4A1 RIS II
Centurion 10" or 12"
KAC URX II
KAC URX III

Here’s what it currently looks like:

2

The C4 10" is a great balance of size and weight on your build. Long enough for your purpose, and light enough to keep weight controllable. The rail looks good too. This is all just my opinion though.
Brandon

3

DD MFR 12.0

4

Looks like the Centurion Arms 10" would work well based on where your handstop is. If you plan on using a X300 up top, go with the 12".

5

Here are two pictures which may or may not be of any help to you.

6

agreed. It’s stupid how light it is.

OP, why do you need quad rails if all you are running is a hand stop? If it’s a looks thing there is no argument from me. part of the reason for owning these damn things is making it look the way you want but I see the FF tubes style being more suited. unless you took off your lights, lasers and tape switches for the photo?

7

Awesome Stick, thanks!

Is that a 10" rail and mid gas in the pics? Looks more like 9" and carbine gas based on how much barrel is showing. Not complaining about the pics by any means, just clarifying what I’m seeing as far as gas block coverage.

One more follow-up question: As I’m selling my DD barrel nut with the rail, and the Centurion rail uses a std barrel nut, is a barrel nut a barrel nut? They’ve got a drawer full of them at my LGC where they’ve done rail installs, or do I need to go buy a DD or other “known quality” one?

Thanks!

8

I did, or rather hadn’t put them back on yet. Here’s how the front end normally works:

Add a bipod to that on occasion and I’m using 3 of the 4 rails. I also do prefer the looks of the rail to the tubes.

9

I know you aren’t really looking at tubes, but I’ll try to steer you toward the Samson EVO.

It’s insanely light, comfortable in the hand, and you can attach rails to the sections where you’d need to put your light and hand stop. That’s basically the same system I run, and I’m definitely stoked about the weight it saves. They’re pretty reasonably priced too.

10

The Mk-18 rail generally won’t work on a mid length, without trimming a bit off the bottom of the gas block.

11

Thanks for the info Todd. Does that apply to the DD low pro gasblock as well?

12

From what I understand there are gas blocks that already will work with the Mk.18 anyway with no modification. Just research.

I’m personally stuck between URXIII and RISII

What’s great about the URXIII is it has the built in front sight so you can imagine you’re sort of saving on a front backup. However, if you already have a front sight, then get the URXIII.1

RISII is a great rail, weighs more than the light when of equal length, however. The advantage to me is the ability to clean it and the thinner grip.

I’m probably going to get a URXIII rifle length (yes they make a mid but it’s not good for standard middys it appears?) for the weight savings. I hike/hunt with my gun and so I think I can appreciate it. It also has the right amount of space for where I put my hand-stop.

I’d do RISII for a “go-to-war” gun.

To that end, Centurion makes a rail everyone seems to be happy with.

13

I may have actually ruled out the URX III for the same reasons I ruled out the tubes. It’s basically the same deal. I’ve never been very impressed with the integral KAC front sights. Always a little flimsy to me. Kevin B posed somewhere about it getting hot quickly too.

That 10" Centurion is looking better and better. I found an old post about a discount code. Is there still a valid one?

14

Oh and recall there’s Geissele and Noveske modular rail systems coming soon.

Edit: Also, URXIII.2 has no front sight built in. Just fyi. - flimsy could be true. Thanks for the thought.

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URX 3.1

16

Thanks I just remembered I got that wrong. It is indeed 3.1 not 3.2

17

Add another vote for the MFR. A buddy just picked up my DDM4 v7 with the MFR and asked if it was the LW rifle because of how light the MFR is.

18

Out of the rails the OP listed, I only have hands on experience with the Centurion. I have the midlength cutout rail, not the 10" version.

I personally would shy away from the URX rails, only because I want the ability to install and remove them myself, and be able to do it without a $250+ barrel nut wrench.

So that leaves the RIS II and the Centurion. I’d personally pick the Centurion, because it is what I own, and have experience with. I like the profile, the top to bottom and side to side proportion feels balanced (compared to say the proportions of the DD Lite, which has a more “I beam” like profile). Additionally, it doesn’t require a proprietary barrel nut (not that I find that to be a big deal, but it is convenient) and it has built in QD swivel cups at both the front and rear of the rail. It also is easily removable to clean the outside of the barrel, if needed (which could be important to those shooting near/in marine environments).

As far as the RIS II goes, I haven’t seen one in person, so I can’t really comment on it. The reviews I have read on this site from end users of the rail have been favorable, as have the reviews from all the rails listed by the OP.

19

I will not buy another URX with integrated front sight. I broke one clean off and bent another. Luckily, KAC sent out a replacement. IF I were to buy another KAC rail, it would be the URX 3.1. Now, as much as I like them, I just don’t see this happening since I don’t own the wrench and won’t consider buying the wrench until they lower the price.

I’ve owned 3 URX II’s, one a lightweight. I also have both RIS II’s, the M4A1 and Mk18 on a 14.5" and 10.5" respectively. They are very robust and feel great due to their profile. I no longer run rail covers, just the LaRue clips and ladder style covers.

I would love a Centurion, and likely will when I get around to doing a 12.5", possibly a Kino with the mid length cutout. One of the reasons I went with the RIS II on my 14.5" was the fact I’ve been using the RIS II Mk18 on my 10.5" LMT and wanted them the same. If not, I would have likely gone with a Centurion.

If I wanted to run a FSB, I’d certainly go with the Centurion cutout rails. For BUIS, I like the RIS II’s.

20

If you have the DD pinned low pro (with the really low and rounded, no-set-screw underside) it will clear it. Anything else and you’ll have to dremel atleast 2mm off the underside to get a good enough clearance.
I love the mk18 but that’s just because it’s exactly the length I need to run my weapon the way I do. Nothing more, nothing less.