This is an overview of the new Daniel Defense MFR 12.0 Rail that was used on a BCM light weight upper build. Other aspects of the build will also be addressed. Additonally, there will be a brief, unscientific comparison to the Troy VTAC rail

I decided to build a second upper (which may... awe who am I kidding, will turn into another complete rifle) and chose a lighter-weight route. I waited patiently for BCM to get their 14.5" LW middies in and snatched one up when they became available. I've used their standard barrel version before and was thoroughly satisfied, so I decided to stick with them again.

The DD MFR looked interesting and since I already had a VTAC rail on another upper, I decide to try it. There wasn't too much info out there from the end-user, so I figured I'd also take the opportunity to do a write up on it as well.

To make the 14.5" NFA friendly, a Battlecomp 1.5 was tentatively chosen. After receiving the upper and measuring the barrel + A2, I found that my 14.5" was really a 15" (WTF over?) which was made 16 3/16" with an A2. This opened the door to other standard muzzle devices. I had previously read about the Griffin Armament M4-SD Compensator which performed nearly identically to the Battlecomp, save for a little more flash (and ~$50 less to boot), so I ordered one from Joe Bob Outfitters using code "carolina" to save a few more bucks.

After watching surf's Youtube vid on shaving an FSB (seen here http://www.youtube.com/watch?v=I5rPPyYdFUs) I decided to give it a whirl. I practiced on a .750 FSB I had lying around then it was on to the real one. Let me say that the taper pins on this upper were UNREAL! I spent the better part of 2 hours trying to bang those SOBs out. I used a dremel briefly, and eventually went to the concrete garage floor and used a large mallet and and struck those things 10-15 times like Thor while working in profanity the way others might work in oils or clay (+10 internet points if you can name the movie).

The MFR rail and M4-SD arrived a couple days apart and I went to a local 'smith to get the proprietary barrel nut put on and comp pinned. Here's what I came home with:




Due to the narrowness of the barrel nut rail interface ring thingy in the rear of the rail I had to do additional contouring of the FSB. A fair warning, use a pinned low-pro gas block, set screw version, or shaved FSB as I don't believe a clamp-on style will have enough clearance.


The railed sections provide with rail allow the user to add or remove sections with the rail mounted. Another improvement over the VTAC I have on another upper. The attachment hardware on the back of the rail section is connected to two hex head screws on the railed side. When the screws are loosened, the mounts extend away from the section so they can be slid into the holes (that's what she said) of the MFR, one after the other. Once in position, tighten the screws and you're good to go.


While looking over the rail I didn't immediately notice an anti-rotation feature, and when looking at the mounting system, which is four set screws positioned equi-distant around the rail at 45* which sit in a 360* groove, it looked like there might have been some cause for concern.


However, closer inspection showed that the tube extended about 1/16" past the top rail on the sides and indexed quite nicely on both sides of the upper reciever, a feature devoid of in the VTAC design.


After sliding the rail over the barrel onto the barrel nut, it felt rather loose, as though something was not mating up correctly. Also, there was a substantial gap between the upper and tube.


I decide to RTFI and DD mentioned this looseness as a point at which to line the tube and receiver rails up before installing the set screws. Upon tighting the set screws, the MFR was pulled back towards the upper receiver and the gap was sufficiently closed.


Now for a brief comparison between the MFR and VTAC.


I have been using the VTAC for several months and like it alot, but feel it could benefit from a stronger mounting system, which the MFR has. The MFR is noticeably larger than the VTAC, though not by much. The outer diameter of the MFR is 1.76" verse the 1.74" of the VTAC. Here's a measurement of the outer circumference which shows the minimal difference, about 1/16".




I personally like the feel of the VTAC in my hands better, not necessarily due to the smaller diameter, but the channeling running the length of the rail provides for a better feel and texture not present on the MFR.

After installing the two rails, I have much more confidence in the durability of the MFR over the VTAC, albeit at a higher price point. MSRP on the MFR is $249 but can be had for much less with some effective searching (i.e. sku/part number).



Thanks for reading and I hope this was beneficial.

Thanks for the review.

but....

Leads me to wonder if you are measuring your barrel in the correct legal way. The correct way to measure the barrel is via a rod down the barrel, from the closed bolt face to the muzzle. If you include the barrel extension on an AR barrel you'll get the extra 1/2" which is not part of the legal barrel length.

Just wanted to give you a heads up to potentially keep you from a headache down the road, if it's all good then all good

Thanks for the writeup. I'm taking a hard look at this rail for my patrol rifle.

Thanks guys. I didn't mention it in the review, but this is my patrol rifle setup. I've got about 1,000 rounds through it on my own time and another ~750 in A 2.5 day patrol rifle class.

I'm completely satisfied with it. No shift/rotation from use or perceived flex when shooting off barricades. I'll gladly recommend it to my fellow LEOs.

I really appreciate your review of the MFR! If you dont mind me asking, with it being so lightweight and thin, does it ever get hot while shooting normally? I would expect it to with a few mag dumps but i was curious if you can use the rail for a hand grip if you didnt want to use a foregrip thanks bro!

As far as sling options with this rail im assuming the only way is to buy the optional rail and sling mounts from DD? It would have been awesomeif they were incorporated!

I've had my MFR hot and I did need gloves. I was running the gun as hard as I could sometimes and sent 200rds downrange in 15 minutes. You couldn't hold onto it without gloves either.
Due to the way I shoot, my Magpul RVG puts my hand directly under the gas block. You're keenly aware of the intensity of the heat each trigger pull. I recommend baseball gloves of some type.

http://www.impactweaponscomponents.com/product/qd-rotation-limited-mount/

Until ya'll come out with the goods, I'll be over here ghetto-rigging stuff.



Would love to see your proprietary line, or some team up with IWC.

A machine shop in town did the slot for me. I'm not advocating that everyone do this, but this is how I prefer to run my VFG

The gap is normal. Typically is .025" or less.