How To Install the Daniel Defense MFR Handguard

How To Install the Daniel Defense MFR Handguard

The MFR Rail System is a full-length, free-float, M-LOK® handguard for the AR-15 from Daniel Defense. The MFR’s mounting system is pretty similar to other Daniel Defense handguards, but it requires a few tricks. Brownells Gun Tech™ Caleb Savant shows us exactly how to install it. The MFR is designed to fit a standard mil-spec AR-15 upper receiver. It will also fit a machined billet upper that is cut to mil-spec dimensions at the front (Caleb shows us where).

TOOLS: You’ll need the (1) barrel nut wrench, (2) ball-tip hex wrench, and (3) tube of thread-locker that came with the MFR Rail. You’ll also need (4) a bench vise, (5) an adjustable torque driver, (6) the Midwest Industries Upper Receiver Rod or similar device to hold the upper receiver in the vise, and (7) Brownells Action Lube Plus® or similar high-quality gun grease.

PHASE 1: Use the Upper Receiver Rod or a vise block to clamp the receiver securely in the vise. Put a little Action Lube Plus on the barrel extension, slide the barrel into the receiver, and put a dab of grease on the barrel extension’s front shoulder. Get the mounting plate that has tabs protruding from one side and insert the bolts through the holes from the tab side. Slide the plate over the barrel, with tab side facing TOWARD the receiver. Apply some lube to the threads of the barrel nut, slide it over the barrel, and hand-tighten it onto the receiver. Tighten the barrel nut the rest of the way using the Daniel Defense wrench and your adjustable torque driver set to about 35 ft.-lbs.

PHASE 2: Slide the other MFR mounting plate over the barrel with the INLETTED side facing the bolts (flange side toward the muzzle) and press it up against the first plate. The bolts will go through the holes in Plate #2. Install your gas block and gas tube. You’ll know you have the MFR plates properly oriented if holes line up to allow the gas tube to slide into the receiver! Slide on the handguard up to the bolts. Put a little thread-locker on each bolt. Use the hex wrench to snug up the bolts. Don’t tighten them all the way yet……

PHASE 3: Check for gaps between the handguard, the mounting plates, and the front of the receiver. If everything’s snug, tighten the bolts the rest of the way. There’s no specific torque setting. Just make ’em tight enough so the MFR is securely anchored with no wobble or play.

DONE: Your Daniel Defense MFR Rail System handguard is properly installed on the upper receiver. It’s time to add your chosen muzzle device and whatever accessories you want to put on the MFR!

NOTE: Products in this video are to be used only for lawful purposes, including hunting, self-defense, and competitive or recreational shooting. If you purchase any of them, you are responsible for understanding and complying with all federal, state, and local laws that apply to the purchase, possession, and use of these products.


  1. Daniel Ferguson on March 6, 2023 at 2:30 am

    Can you reuse a gas block and gas tube from one bill to another?

  2. AkAllDay on March 6, 2023 at 2:31 am

    Install? Not on youtube for kids. Might have to consider content uploads to Rumble 😂

  3. Wm H on March 6, 2023 at 2:34 am

    Starting to look like a LaRue upper. Interesting.

  4. thatsthewayitgoes9 on March 6, 2023 at 2:36 am

    Wow. Brutal comments🤣

  5. UNCLEBOB 540i on March 6, 2023 at 2:39 am

    Excellent tutorial as always. Thank you for reminding everyone that when it comes to Loctite, a little goes a long way. Same can be said about anti-seize compound. Also not to over torque. Interesting how smiths seem to be split on the position of torque wrench on barrel nut wrench. Some say 90, some say in line. I have done both and haven’t seen a noticeable difference.

  6. Dino Nucci on March 6, 2023 at 2:41 am

    Good vid, pos product

  7. michael westcott on March 6, 2023 at 2:42 am

    Clean is the way 👍

  8. Tommy Johnsen on March 6, 2023 at 2:42 am

    What QD studs do you recommend for the DD’s QD points?

  9. S O on March 6, 2023 at 2:44 am

    Thanks for the video, I recently purchased a DDM4v9 , and quickly discovered that my iron sites would not co-witness to The HWS without adjusting windage all the way to one side, after watching your video I decided to loosen the hand guard and basically reinstall using the star pattern as shown paying close attention to the alignment with the muzzle end of the barrel which solved my problem , now everything lines up perfectly. Thanks again

  10. Cliff Kirby on March 6, 2023 at 2:48 am

    Do you guys have a Ruger precision rifle 6.5 barrel in stock.

  11. Chris Sewell on March 6, 2023 at 2:49 am

    They look good, but DAMN! I’d need a monkey, a dead hooker, and a bottle of rum to install that thing!

  12. Mr Short on March 6, 2023 at 2:50 am

    awesome content very educational: what ever happened to the larger inner diameter Mlok handguards. the newer slim mlok handguards suck. especially for those of us with a larger grip

  13. Makingnewnamesisdumb on March 6, 2023 at 2:52 am

    That rail is a MFR to get on.

  14. James Carpenter on March 6, 2023 at 2:52 am

    Will y’all be making a rumble channel soon?

  15. Mosca Sucio on March 6, 2023 at 2:52 am

    Good video, but that handguard is too big.

  16. cvillefarmer on March 6, 2023 at 2:55 am

    Wish the mk18 uppers were in stock from you…

  17. Chris Sewell on March 6, 2023 at 2:55 am

    Is this legal and morally ethical to watch such witchcraft?

  18. Charles Armentrout on March 6, 2023 at 2:56 am

    Please start a class action suit when you get the boot!!!! Love your channel a lot 💗!!!

  19. Bob Pritchard on March 6, 2023 at 2:56 am

    So I do have a question about the handrail. What is the part number for the one used on AR-10?

  20. Pong Li on March 6, 2023 at 2:58 am

    These handguards are extremely difficult to be aligned up/down left/right with the stripped upper. Even if you use a tool or a scope mount to bridge the upper and handguard. If you are using ironsights you will never have them aligned enough to where the rear peep sight is in the middle of the sight. Always end up either way to the left or to the right.

  21. Jerrold Kazynski on March 6, 2023 at 3:00 am

    And add a rag to the needed tool list.
    Other than that minor oversight, Great How-to video.

  22. Eric Soto Hernandez on March 6, 2023 at 3:01 am

    These videos are so relaxing… gun asmr

  23. CRinJersey on March 6, 2023 at 3:02 am

    Caleb can build an AR in 5min 30 secs flat, from the aluminum stock to hammer forging the barrel

  24. Pyreleaf on March 6, 2023 at 3:03 am

    YouTube auto-subtitles seems to think your torque wrench wasn’t made in America.

  25. A Physics Professor on March 6, 2023 at 3:03 am

    cut in half

  26. kb04svt on March 6, 2023 at 3:05 am

    DD would not send that out like tbat

  27. robot buster on March 6, 2023 at 3:05 am

    That handguard would look good in Wolf Gray Aluma-Hyde

  28. Jo Bu on March 6, 2023 at 3:05 am

    Every pro… "That torque wrench part was very questionable."

  29. 30Plus1 on March 6, 2023 at 3:07 am

    Nicely done. Wish this had been available when I installed this handguard.

  30. kb04svt on March 6, 2023 at 3:07 am

    No dimple? No pinned gas block?!

  31. Tim Liu on March 6, 2023 at 3:07 am

    You forgot the most important tool of them all, a angle grinder because DD makes their low profile gas blocks impossible to remove from the factory

  32. All Phase Elec on March 6, 2023 at 3:07 am


    You didn’t mention or discuss anything about the Barrel Install Head Spacing??


  33. Jase Tyler on March 6, 2023 at 3:12 am

    Top rail of the hand guards a tad low compared to the upper and left to right is off

  34. Happy Home on March 6, 2023 at 3:14 am

    What a marvelous how-to video. Multiple points were important for me. The receiver rod – had never seen one before, and after all my struggles trying to secure a firearm for barrel/handguard work . . . This hand guard is a MUCH smarter design than that one that came with my extra expensive Wilson Combat rifle (pre-COVID). That barrel nut had to be torqued a ridiculous amount of get the next opening for the gas tube to line up.

  35. Chris Sewell on March 6, 2023 at 3:15 am

    Just remeber kids… If at first it don’t fit?! Break out the Bastard File, and go to grinding! Get’r done!

  36. Jeff Lawrence on March 6, 2023 at 3:16 am

    Is it just me or does everything in this video look like it’s from 1970

  37. Black Flag on March 6, 2023 at 3:17 am

    Seems a bit over complicated.

  38. Austin Cobb on March 6, 2023 at 3:19 am

    You have to install that qd point over one of the existing holes for it to be usable. This makes all the other points unusable, unless you buy more of the qd points, and they are never in stock.

  39. Floyd Dwayne Viernum on March 6, 2023 at 3:19 am

    Nicely done. Thank you. And nice manicure.

  40. Donald Hollingsworth on March 6, 2023 at 3:22 am

    I noticed you didn’t set the head space.

  41. Conrad Szymczak on March 6, 2023 at 3:24 am

    Good. Stick with this stuff and forget the fru fru crap….

  42. laszlo vandor on March 6, 2023 at 3:25 am


  43. George Moomaw on March 6, 2023 at 3:25 am

    Caleb is the quintessential pro. I am the quintessential doofus. Without his guidances, I would have never attempted this mod.
    Thanks Brownells. Thanks Caleb.

  44. Nunya Binness on March 6, 2023 at 3:27 am

    They named it the mothereffer? 🤣😭

  45. Eric Ward on March 6, 2023 at 3:28 am

    Is there a reason why you didn’t season the threads while installing the barrel nut?

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