Desert Tech MDR Ejection Mechanism Explained

Desert Tech MDR is probably one of the most awaited rifles on the market. And no surprise that people keep wondering about various aspects of its mechanism. Perhaps Desert Tech has been stormed with such questions. Anyway, they started releasing short videos on their YouTube channel answering the questions people ask.

Recently they’ve released a video explaining how the rifle will work (eject) without the ejection port chute. The latter guides ejecting cases forward. As you know MDR pushes the cases forward at an angle from the small window on the ejection port cover. By answering that question they also show more details of the weapon’s ejection mechanism. Apparently, the ejector is an articulating lever, which pushes the fired case into a clip inside the ejection port chute. Then, on its forward stroke, bolt pushes the fired cases out of the gun. So, in case if the chute isn’t in place, that articulated part will work as a normal ejector and will eject the brass out of the gun during the rearward motion of reciprocating parts. Here is that video:

Of course, innovations are always interesting to see in the firearms designs. However, I think these kind of mechanical solutions are bordering with not really being “field” practical. I hope I am mistaken and we’ll see a new super rifle finally released. However, as the history shows us, when it comes to combat weapons, the simplicity is usually more desirable than an overly complicated mechanism which gives a non-significant advantage at the cost of being prone to malfunctions.





Hrachya H

Being a lifelong firearms enthusiast, Hrachya always enjoys studying design, technology and history of guns and ammunition. His knowledge of Russian allows him to translate and make Russian/Soviet/Combloc small arms related information available for the English speaking audience.
Should you need to contact him, feel free to shoot him a message at TFBHrachyaH@gmail.com


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  • Petto

    I can see some potential jams with that thing , it looks cool tho

    now i wonder when they really start to sell these things

    • hikerguy

      I think it will function fine, but will require maintenance to work. It does look like it is sealed well to prevent outside fouling from getting in. I know Desert Tech makes high quality stuff, so this ejector won’t be released until it is right. Like you I can’t wait to the finished product is on the streets.

      • noob

        the key will be keeping fouling out of the scissor action and the little spring loaded clip that grasps the empty case in the ejection chute.

        any buildup there will be on the long ends of the lever and the relatively low forces generated by the cartridge moving sideways might not be enough to overcome the resistance (especially if something like sand grains get in and wedge the surfaces apart.)

        also I hope they make a way to keep the ejection chute captive when inspecting the chamber. In the video he pops the chute off by pressing a spring loaded catch and sets aside.

        If I left a camo colored ejection chute in leaf litter in the dark, I’d need a magnet to find it again.

  • That’s interesting. I wonder, how does one check the chamber to make sure a round is chambered without removing the feed chute?

    The FS2000 has the little “toilet seat lid” at the top that allows you to view the chamber, wonder if this has something similar, or even like a loaded chamber indicator pin.

    • BattleshipGrey
      • QuadGMoto

        This is an older graphic. The covers have been redesigned twice since the ones shown in this image.

    • QuadGMoto

      The covers (on both sides) are easily removable. The tab at the rear can be pushed forward and the cover comes right off.

      I haven’t seen anything about a loaded chamber indicator.

      It should also be possible to see the chamber when the magazine is removed and the bolt is pulled back.

  • XT6Wagon

    There is something wrong when you can say “buy an Aug or Tavor and save money”.

    years late, hundreds of dollars overpriced.

    • roguetechie

      I am one of the people who complain about the price of bullpups, but honestly complaining that the desert tech is over priced is kinda silly.

      Because you know what you can’t get with $2600?

      A 308 AUG or Tavor

      • Flounder

        But you can get 2 RFBs…

        • roguetechie

          Speaking as a former RFB owner … I’d take the desert tech.

          • Drew Coleman

            The difference is that you can actually buy an RFB, they are for sale.

          • roguetechie

            True, but I wouldn’t.

            I’ve considered buying an RDB though.

            However other than my skeli rifle fund the rest of my money is going towards filing a couple patents and building DIY guns and tools that are my own designs.

          • noob

            I’m curious about the X11 Skeli – is the permanently attached pistol grip going to impact modularity since you can’t change the ergonomics?

          • roguetechie

            Newer versions they showed at SHOT this year deleted the permanently attached grip for a standard AR grip.

      • Vhyrus

        Right now you can’t get a MDR either, so…..

        • roguetechie

          Believe me, I’m well aware of this too LOL…

          Personally, I reallocated funds I had saved for one to get a skeli when it comes out.

      • Zachary marrs

        And you have a .308 MDR in your hands right now?

        • roguetechie

          Nope, and I won’t be buying one when they finally hit shelves.

          Some of this comes down to my realization that I just don’t have any desire to own or shoot 308’s.

          Another part of it is that the AUG patent has hit expiration.

          Another part is that I’ve come to realize that most of my enjoyment with guns comes from designing and manufacturing new parts for my guns and or designing and building entire new guns based around commonly available replacement parts for existing guns to one degree or another.

          There’s a bunch more parts but the final major nail in the coffin of me buying an MDR is that the Skeli gun is something I want more so that’s what my MDR fund is going to.

          • mig1nc

            I’m curious to hear your thoughts, why do you prefer the X11?

          • roguetechie

            It has a feature set that puts it in a class with $2000+ rifles at a pretty desirable price point.

            Plus I’ll be able to convert it to left side ejection and that will be nice since I shoot left handed. I’m also interested in the feature set and it’s internals, so I’d like to have one of my own that I can disassemble and measure and generally mess with.

            Plus it will satisfy my need for new/shiny while I design and fab my AUG 2.0 style gun and work towards completing my general bullpup research.

  • Kinda surprised the ejection doesn’t use EM drive or something, given the timeframe involved.

    • JumpIf NotZero

      Its tough because you really need to do the testing in space.

      • roguetechie

        But Nevada isn’t far at all from desert tech’s test range… Tr-3b’s could pick them up 3 times a week to speed up the development cycle…

        I’m gonna write my congressman…

  • 22winmag

    I love it when “most awaited” firearms flop.

    Just sayin’

    • Walter J

      Probably can’t afford them anyway….

      • FulMetlJakit

        True, and for those who can, enjoy the skewed global economy that allows you to buy a rifle that costs 7 years wages for the majority of people on Earth.

  • GhostTrain81

    I think the downward ejection of the RDB is pure genius.

    The MDR’s ejection chute is neat but I subscribe to some basic principles of systems engineering –

    1)more steps (i.e. feeding to the chute device): more possibility of errors / malfunctions.
    2)more moving parts: more points of failure.

    • QuadGMoto

      Your point about simplicity is spot on.

      However, how well is the RDB safe from environmental fouling? The wide open ejection port on the bottom seems like an invitation for anything and everything to get into the most important moving parts in the system.

      One of the more interesting results from InRange’s mud tests is that stuff goes in easier than it comes out. They expected rifles that provided for fouling substances to exit the system to do better, but it turns out the tighter, more sealed rifles tend to do better because they don’t let stuff in to begin with.

      The MDR is far more sealed than the RDB, which I would think leads to better reliability even if all else is equal. (As if the QC on the RDB was good enough to trust your life to.)

      • roguetechie

        I’ve often looked at the RDB and the promotional poster that shows what’s going on inside and thought about how you could take that 2 or 3 extra steps kellgren designs never seem to take that takes something from cool range toy to bona fide trust your life to this guns.

      • noob

        InRange TV and Ian from Forgotten Weapons shoveled some mud up the big RDB ejection port, and yes their rather extreme mud test managed to prevent the bolt from going all the way back when firing and they had to manually cycle the action.

    • Ebby123

      Respectfully, simplicity is usually what poorly designed products have to have in place of adequate engineering.

      None of Browning’s designs were simple, yet many are still in service today because he did the engineering work to make them viable.

      Most often simple designs are simple because the designer couldn’t imagine anything more effective.

      • Joshua

        Uh huh….

      • GhostTrain81

        I think the trade-off is what’s key.

        My skepticism of the MDR’s forward ejector thingy is that it’s an extra process (with moving parts) that is added to control the rather the violent high pressured process of getting the brass away from the firearm. Does the risk of adding this extra step outweigh what you get in return?

        My view is just that the risk from the added complexity to enable forward ejection (mainly the proper ejection of the next round) possibly outweighs the few benefits (ambidexterity?).

        But heck I could be wrong, and this contraption is darn super reliable 100% of the time to make having it attached or not a moot point.

        • QuadGMoto

          FYI, DT has said that the rifle will not operate without the scissors ejector cover in place. It can be operated without the chute cover.

        • roguetechie

          I know what you’re saying, but here’s something for your consideration.

          The Russians have one production rifle and at least one experimental/limited issue bullpup both of which use forward ejection systems biased to one side or the other like the MDR’s. ST Kinetics also has their BMCR design which also uses a biased forward ejection system. (Boo STK kinetics for not even considering sales to the American consumer!!)

          Now back to the Russians. The Russian PRODUCTION bullpup using this type of mechanism also has the added stress on the design of being designed for both land use and under water as well.

          The Russians are nothing if not pragmatic which leads me to believe that they have managed to design and produce guns with this sort of ejection which are reliable enough for issue to their equivalent of Navy SEALS. Information about the mechanism and the ADS rifle are understandably pretty tightly held secrets meaning that speculation and pixel counting on pictures are the majority of our information, but I don’t think I’ve overstated by making the inferences I have.

          We then have the mystery green bullpup seen displayed in exhibitions and etc since roughly the same time as AK-12. They’re usually even displayed right next to each other. In later pictures we also see glimpses of it’s spring loaded brass ejection port above the pistol grip.

          I’ve actually recently found a couple Russian patents and a few pictures from interesting angles of guns in the wild which give at least a partial idea of how it’s ejection system works, and making it clear that it’s a different system than the ADS uses.

          My point here is that the Russians at least consider this sort of ejection concept reliable and robust enough to keep working on it as well as having a production gun designed to handle very extreme conditions.

      • BrandonAKsALot

        Personally, I think it’s not the case of simplicity vs complexity. It’s coming up with a successful design and then simplifying said design as much as possible while still achieving the desired goal. Things don’t have to be simplistic to work well, they have to be well engineered as you said, and have as much unnecessary complexity removed.

        The F(S)2000’s ejection system is more complex than a AR, but it’s extremely well designed with minimal extra parts and it works flawlessly.

      • Vhyrus

        Simply not true. The browning short recoil system is one of the simplest self loading designs ever made, which is why it is copied on nearly every commercial handgun. Do you know what made it better? Removing the camming lug at the bottom in place of a simpler slide cut out and hook system.

        • roguetechie

          Unlike 5th gen fighter jets the old simplicate and make lighter chestnut definitely applies to firearms.

          There’s also the fact that really simple and reliable firearm designs often have a very high level of sophistication and very clever engineering hidden in what appear to be very simple parts.

    • roguetechie

      I really like the RDB design too, and maybe one day I’ll buy one.

  • I didn’t see anything about it ejecting your hopes that it will ever hit the market…inaccurate video.

  • Joshua

    ……

    I hear that by adding an extra 8-9 moving parts to the extraction and ejection system one can truly enhance a rifles reliable function……Sad no one ever….Except these guys apparently.

    • Ebby123

      Said the random, uninformed stranger on the internet, who had never designed so much as a soap-box derby car.

      • Joshua

        I’ve just spent a lot of time in the military is all.

        I clearly know nothing of small arms.

        • QuadGMoto

          Experience behind a rifle is not necessarily the same as engineering expertise. You may be able to point out where things have gone wrong with existing systems without being able to identify the tradeoffs that resulted in that design or ways of effectively fixing it.

          (See the discussion started by GhostTrain81 for a good discussion of simplicity, reliability, and functionality.)

        • roguetechie

          Actually from what I’ve seen this is usually the case….

          A large percentage of the FUD still floating around the gun world is perpetuated and perpetrated by current and former service military personnel…

          I wouldn’t hire a fireman to design my city’s next pump truck either though so it’s not like I’m singling military personnel out by saying this.

          If anything it’s understandable that you guys would have strong opinions about topics gun related even though short of 18b’s the practical education and etc about firearms you’re likely to receive in the military does not actually provide a sound foundation for which to build your opinions on.

      • Tinkerer

        Aren’t we all random, uninformed strangers on the Internet?

    • QuadGMoto

      DesertTech is putting the rifle through NATO testing to make sure it’s reliable.

      As an example of how well that’s working out, they had failures early on when they had a range night at Shot Show 2017. It turns out there was some 6.5 Creedmoor ammo mixed in with their .308. Once they figured it out, they got a batch of unmixed ammo and the guns ran without failure for the rest of the night.

  • AJ187

    Did I make it in before someone tells us to buy a Tavor because it’s “battle proven.” Because it was born that way I guess….

  • Malthrak

    If this were 2012…people might be excited.

    The MDR hype train is dead, the bullpup market is now served admirably by the Aug, RDB, RFB, Tavor and soon the Atrax, all at dramatically lower pricepoints.

    A couple years late and a thousand dollars short….and still no release date.

  • Vitor Roma

    This design is great, let me explain why:

    The bolt can focus on being a bolt, without sacrificing material and space to house a extractor and ejector. The bolt is able to be made simpler and more robust.

    The extractor and ejector can also be made very robust, since they are not limited by having to be part of a bolt.

    • roguetechie

      Except your extractor needs to be on the bolt unless you know how to teleport

      • noob

        hmm not on this gun, but if you were designing an “extractorless” pistol caliber blowback SMG could you aggressively flute the chamber to have the case self-extract without making the bolt open so early that the gun is unsafe?

        • roguetechie

          In theory.. Probably if and only if you also had exactly the right case taper…

          Even then though it would be extremely finicky and likely only work within an extremely narrow range of projectile weights, pressure curves, and etc.

          Not to mention that if you think AR’s s*** where they eat this damn thing is the equivalent of an AR15 binge drinking miralax!

  • mazkact

    Get one out to Ian and Karl for a mud test ASAP 🙂 The Tavor did not fare well.

    • noob

      nor the RDB