DD MFR/DDM4 Rail?

[dirkmagurk]

Has anyone here experienced their Daniel Defense MFR/DDM4 rail loosening and canting over time or with hard use? After looking over my 15" MFR I noticed that the anti-rotation tabs have a significant gap between them and the receiver. I haven't subjected mine to hard use yet but it seems over time the rail could develop a cant. Any helpful information from actual experience is greatly appreciated! I am asking because I'm thinking of picking up one of their 11.5" uppers with either the MFR MLOK or DDM4 quad rail.

[GH41]

I don't own one but evidently you are not the first >>> https://www.youtube.com/watch?v=QQOa...utu.be&t=1m25s

[justin_247]

Has anyone here experienced their Daniel Defense MFR/DDM4 rail loosening and canting over time or with hard use? After looking over my 15" MFR I noticed that the anti-rotation tabs have a significant gap between them and the receiver. I haven't subjected mine to hard use yet but it seems over time the rail could develop a cant. Any helpful information from actual experience is greatly appreciated! I am asking because I'm thinking of picking up one of their 11.5" uppers with either the MFR MLOK or DDM4 quad rail.

Yes, they have a gap. They aren't truly "anti-rotation" tabs... they're more designed to keep the rail from completely rotating if it does come lose if the poo hits the fan (this is why you should never bridge optics across rails). The original DD Lite rail didn't have any anti-rotation tabs at all.

If it's installed correctly, you should never need them. Many other companies have rails with similarly designed "anti-rotation" tabs that never touch the upper receiver.

[dirkmagurk]

I don't own one but evidently you are not the first >>> https://www.youtube.com/watch?v=QQOa...utu.be&t=1m25s

Damn that is exactly what I was thinking could happen. It's a shame because everything else about my upper is quality. I have the LW barreled version and it is very close to shooting MOA with the right ammo and they actually pin their gas blocks!

[dirkmagurk]

Yes, they have a gap. They aren't truly "anti-rotation" tabs... they're more designed to keep the rail from completely rotating if it does come lose if the poo hits the fan (this is why you should never bridge optics across rails). The original DD Lite rail didn't have any anti-rotation tabs at all.

If it's installed correctly, you should never need them. Many other companies have rails with similarly designed "anti-rotation" tabs that never touch the upper receiver.

This is the first free float rail system I've seen with such a big gap between the tabs and upper receiver. I know better than to mount optics across a non monolithic railed upper, my concern is throwing off my BUIS zero. I'm one of the weirdos that still trains with irons to stay proficent in the rare event they are needed.

[justin_247]

This is the first free float rail system I've seen with such a big gap between the tabs and upper receiver. I know better than to mount optics across a non monolithic railed upper, my concern is throwing off my BUIS zero. I'm one of the weirdos that still trains with irons to stay proficent in the rare event they are needed.

I'm not saying it's the best system, but I think you can trust it. I certainly wouldn't go buying a whole new upper or swapping out a rail because of the concern unless you have a problem with it yourself. Take a white marker and draw little indexing lines on the screws, and then you can check to make sure the lines are aligned each time you clean the weapon. That should prevent any potential problems from developing.

In the future... if BUIS is really a huge deal for you, I'd avoid using rail-mounted BUIS entirely, and instead go with some kind of fixed setup with a front sight post pinned to the barrel. At that point, what kind of rail or handguard you choose depends on what kinds of accessories you want to use with it.

[Finestkind]

I will trust a Daniel over many other rifles any day of the week.


Finestkind

[AKDoug]

What do you plan to do with it? My DDM4V7 with the original MFR is knocking on 10,000 rounds down the pipe now and is a veteran of two RedBack One classes, a Frank Proctor class and a half dozen local classes. Zero issues with the that MFR holding zero with irons. Just my experience with a sample of one. If you want a no bull shit not likely to ever fail iron sight rifle, get one with a FSB front sight.

[Beat Trash]

Between myself, my wife and my son, we have 4 DD rifles with MFR rails on them. Two of the guns are factory built DDM4V7's, and two are factory built DDm4V5's that I swapped out the quad rail for the MFR rail once they were available. One of these has been my Patrol Rifle as an inter-city LEO Canine unit supervisor for the last couple of years. My work gun gets banged around a bit, especially when going along as the cover officer on a canine track. One of these rifles has been in Nome Alaska for the last 18 months. Not abused, but not babied either. Zero issues with the MFR rails so far. And at this point, I don't expect there to be any issues.

On the two guns that I had swapped out the quad rails for the MFR rails, I made sure to clean the hardware and apply a dab of blue lock tight during the installation. On the other two guns, I just checked to ensure the hardware was tight when inspecting the new guns. All of these guns run some type of optic with BUIS.

If I wanted a gun that was to be used with just iron sights and remained as durable as possible, then I'd take one of my Colt 6920's and put the factory carry handle back on the gun.

[dirkmagurk]

I appreciate the feedback from everyone and I completely understand that having a FSB is the most rock solid option if running irons. I have a few rifles setup with fixed FSB/gasblocks but they are older builds and my preferences have changed. I now run primarily MLOK free float rails with a X300 mounted at 1200 with fixed front sight and folding rear for use with an Aimpoint in a lower 1/3 QD mount. I've never really introduced myself or given any of my background on this forum but I am active duty with plenty of small arms experience. I have maintained and trained sailors and marines in the use of everything from the M9/M11 to the M2 ma deuce. I am by no means an "operator" and I only say this to avoid the responses that are basic information that any of us with experience are well aware of. I contacted DD and asked about possible issues with this bolt up system. The DD tech told me there were some early samples that had issues with canting due to not leaving the factory properly torqued. I am a huge fan of Daniel Defense and have faith in their products. I only started this thread because I have never seen a gap this size between the "anti-rotation tabs" and upper and was curious if anyone had an issue with it before.