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Author Topic: DT Sponsored MDR Q&A thread.  (Read 2278 times)
ney1
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« on: June 14, 2018, 02:05:49 AM »

Gentlemen,
I apologize I have been off-line for so long, we have been extremely focused on MDR production and fulfilling customer orders and we haven't communicated with our customers like we needed to.

I will try to post official Desert Tech information in this thread so please do not clutter it up.  We will post the answers to questions people are asking so if one person asks a question please don't continually ask the same question and please don't freak out at us if you don't give you a immediate answer to your question.  If anyone has questions please try to list all of your questions in bullet points as concisely as possible in one post and avoid duplication of questions so that we can easily identify them and answer them faster.

I understand that a handful of MDR rifles have run into some issues, I sincerely value everyones feedback and we want to ensure all MDR's are functioning 100% out of the gate.  I want to thank all of you who have been working closely with our warranty department to diagnose any problems that have arisen.  

First I want to give everyone assurance that very few rifles have had the issues that some of you have seen with your rifles on this forum.  But, this is a very public forum with lots of vocal customers and I can respect and appreciate that.  Unfortunately, we at DT already have egg all over our face from our continued production delays so we are already under the microscope and being overly scrutinized.  This added scrutiny and the fact that the MDR is a new breed of rifle has led many to be overly judgmental of the MDR rifle and insinuating issues that aren't real.  Others have had some legitimate issues with their rifles which is regretful.  We have stood behind the MDR 100% and we will continue to take care of every customer has any issues.  Each time an issue arises we are doing everything possible to prevent repeat issues from happening.

I appreciate everyone who has supported us and believed in us very much!

Sincerely

Nicholas Young
CEO, Desert Tech, LLC.

PS.  I will not respond to harassing or hateful posts so please keep conversations professional and courteous.

« Last Edit: June 14, 2018, 03:38:49 AM by ney1 » Logged

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ney1
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« Reply #1 on: June 14, 2018, 02:12:55 AM »

Firstly I will address questions about some of the stuck case issues some have reported as well as provide an update on the 5.56 rifle release.

To address the stuck case issues:
The majority of the stuck case problems have been caused by the ammunition being fired through the MDR.  Initially we had difficulty replicating the stuck case issues and it was because our warranty team was running quality commercial ammunition like; Federal, American Eagle, Remington, and Hornady.  This made so our warranty service was not able too replicate the issue and since it functioned for the warranty tech he returned the rifles.  When those customers tested their rifles they got stuck cases again.  We quickly revised our warranty process to conduct a thorough investigation into the details of what conditions existed at the time the issue occurred so we can exactly replicate the conditions in order to reproduce the problem.  We discovered the several of customers with this issue had stockpiles of cheap surplus ammunition that isn't readily available for us to even purchase it to test.  We understood they had a strong desire to be able to use these stockpiles and those customers have been really great at helping us out and they sent us some of their ammunition to test.  

Issue#1:
We have tested dozens of brands and models of ammunition through the MDR now and we have determined that ammunition by CBC and AM 2030 will not reliably function in the MDR because the brass is too soft.  Some folks have commented that NATO specification ammo should fire in a Nato Spec'd rifle, however I don't believe that NATO specification calls out the hardness of the brass.  Even if a cartridges external dimensions meet NATO spec the brass can still be too soft.  Measuring the hardness of the brass takes specialty equipment which most people don't have access to.  

Issue#2:
We also found that a small percentage of barrels had an unusual ring inside the chamber and our engineers were able to determine that rough handling by the meloniting house caused the ring (while installing them onto their coating fixture.)  Most of the barrels still functioned fine when we tested them however if the ring was too deep it caused additional friction upon ejection increasing the likelihood of stuck cases.  We have replaced a few barrels that exhibited this problem under warranty.  Our meloniting house have redesigned their mounting fixtures to eliminate future issues from occurring.

One Comment: The MDR gas block location is the same far forward as the FN Scar for those who inquired so there is not overpressure issue in the chamber like some have insinuated.  

One More Comment: The MDR's chamber is SAAMI spec and 100% of barrels are verified to headspace properly prior to leaving our facility.  The chamber is meant to fire all SAAMI spec ammunition not just our match ammo.  This is not a match rifle we did not cater it to our match ammo.

5.56 Rifle Release Update
The production polite guns have been been undergoing longevity testing for the past two months.  We have fired over 20,000 rounds through multiple rifles.  We ran into an issue specific to the 5.56 bolt carrier group that did not exist with the .308 win that took some significant engineering to overcome.  We believe the issue is 100% resolved now and next week we will be posting the expected release date (which is very soon) for the 5.56 MDR's.

I look forward to reviewing your many questions.
« Last Edit: June 14, 2018, 03:37:08 AM by ney1 » Logged

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pokemon1989
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« Reply #2 on: June 14, 2018, 02:53:49 AM »

-Will the gas plugs continue to have the brazed in sleeve that has been present in rifles? It seems to be a quick fix that seems sloppy and may create the same over gassing problems with the reduced piston chamber volume.  Also the 6 position gas plug should be a standard feature, not a paid fix for reliability.
-Will there be a redesign with the rail section on the gas block? It seems only useful to get yourself burnt.  There isnít any room for optics and is placed too far forward to be practical.
-Putting wrench flats on the flash hider would be appreciated.
-Are QC issues being resolved through adequate assembly training?  From stiff mag releases to pins falling out and many other instances, there have some quality issues that donít inspire confidence.

Thank you for listening.


Sent from my iPhone using Tapatalk
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ney1
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« Reply #3 on: June 14, 2018, 03:30:09 AM »

-Will the gas plugs continue to have the brazed in sleeve that has been present in rifles? It seems to be a quick fix that seems sloppy and may create the same over gassing problems with the reduced piston chamber volume.  

No they will not.

Also the 6 position gas plug should be a standard feature, not a paid fix for reliability.

This has been requested several times, we are taking the suggestion under advisement, initially the value was designed to satisfy a handful of odd-ball ammunition and suppressor combinations a few folks.  It shouldn't be needed for the majority of MDR owners with normal ammunition and normal machine gun rated suppressors.

-Will there be a redesign with the rail section on the gas block? It seems only useful to get yourself burnt.  There isnít any room for optics and is placed too far forward to be practical.

The intended design was to allow our red dot sight attachment to the gas block to maintain rifle zero when uninstalling and reinstalling the barrel.  We have a sight and mount that is designed to mount on the gas block however I just noticed it can only be purchased through our rifle builder.  We will get it up on the website asap.  https://deserttech.com/rifle-builder.php?r=4  I do realize the gas block picitanny rail has created some undesirable complications but it's too early to make a determination for future models.

-Putting wrench flats on the flash hider would be appreciated.

I agree! 100%

-Are QC issues being resolved through adequate assembly training?  From stiff mag releases to pins falling out and many other instances, there have some quality issues that donít inspire confidence.

We have been very busy hiring and training additional assembly technicians.  We also beefed up our final inspection procedures.  We are doing everything we can to maintain quality in our assembly department.  That is a big part of why you don't see me on here much anymore because we are extremely focused on the production line.

Thank you for listening.

You are very welcome!  Thanks for asking the questions you did!

Sent from my iPhone using Tapatalk
« Last Edit: June 14, 2018, 03:33:30 AM by ney1 » Logged

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Playro
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Robin Rothenfluh, Switzerland


« Reply #4 on: June 14, 2018, 05:02:31 AM »

-When will the .308 (and 5.56) MDR be avaiable overseas in Switzerland?
-Will you start selling Richard Murphies Aluminum Handguard? I'd buy, but we cant export it from US.
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Kind regards,
Robin Rothenfluh from Switzerland
ney1
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« Reply #5 on: June 14, 2018, 05:36:39 AM »

-When will the .308 (and 5.56) MDR be avaiable overseas in Switzerland?

I expect it will be in the fall of this year as we should have our backlog caught up by then.

-Will you start selling Richard Murphies Aluminum Handguard? I'd buy, but we cant export it from US.

I am not familiar with his hand-guard can you share a website link for me please?
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Playro
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Robin Rothenfluh, Switzerland


« Reply #6 on: June 14, 2018, 05:45:46 AM »

Thanks!

I'm unaware of his website, but he's in the Facebook Group (Desert Tech MDR owners Group), where he advertised it. Planed release is 1st July. He has quite some experience with this subject (ACR, Scar etc). He's willing to sell it via DT he told me.
Link to his profile: https://www.facebook.com/richard.karynM
Properties:
-Aluminum
-gas Valve accessible with handguard on
-size of your large over-suppressor-handguard
-directly continues rail from reiceiver & has many Slots
Attached his earlier design.


* Alu handguard design.jpg (32.5 KB, 880x355 - viewed 55 times.)
« Last Edit: June 15, 2018, 08:31:35 AM by Playro » Logged

Kind regards,
Robin Rothenfluh from Switzerland
knipple
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« Reply #7 on: June 14, 2018, 06:09:34 AM »

-Is there any way to reduce the amount of force required to actuate the Magazine Release?  Currently, I can't use the mag release near the trigger while maintaining a firing grip.  I have to shift one of my hands so that I can use my thumb while using the other fingers to pull the thumb into the magazine release.  The Mag Release on the magazine well is easier to operate, but still difficult.

Thanks
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newguy2k3
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« Reply #8 on: June 14, 2018, 06:55:12 AM »

When the mdr either can't fire or requires adjustment to fire some ammo without getting stuck cases that other rifles in the same category (Scar, MWS, Fal, G3,  Rfb, etc) do without issue is that not seen as a problem for what the mdr is advertised and sold as? I'm still sticking cases with the 6position plug on ammo that I've never had an issue with in other autoloaders.

If you tighten up the tolerances on the magazine catch retention bolt and the right side bore it will fix many of the magazine compatibility issues the mdr has which also. The excess clearance in that area leads to in/out play on the actual mag catch. It also is disheartening when the rifle is designed around sr25 pattern mags but it seems to be able to only reliably use 1 brand of mag. Even after I corrected that issue it still doesn't reliably function with Brownells aluminum mags. I haven't had time to inspect further but I believe it's a clearance issue at the back of the mag.

Is anything being done to the trigger bar/trigger linkage? The current design is just a hook and the safety only prevents movement of the bar, not the actual trigger pack. Just looking at it the design doesn't seem safe in the event the rifle is dropped on the muzzle.
« Last Edit: June 14, 2018, 07:12:34 AM by newguy2k3 » Logged
Sdevante
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« Reply #9 on: June 14, 2018, 07:47:19 AM »


Issue#2:
We also found that a small percentage of barrels had an unusual ring inside the chamber and our engineers were able to determine that rough handling by the meloniting house caused the ring (while installing them onto their coating fixture.)  


Any way to visually inspect for this problem prior to sending in for warranty work? [EDIT for clarity] What I mean to say is, if I look inside the chamber and have this problem, would it be obvious?
« Last Edit: June 14, 2018, 12:28:13 PM by Sdevante » Logged
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« Reply #10 on: June 14, 2018, 08:20:40 AM »

@ney1 thank you for doing this. Before I ask my questions, I would like to have MDR owners voice their thoughts first.

Thank you for getting back on the forum.
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CabbitOne
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« Reply #11 on: June 14, 2018, 12:32:47 PM »

-Is there any way to reduce the amount of force required to actuate the Magazine Release?  Currently, I can't use the mag release near the trigger while maintaining a firing grip.  I have to shift one of my hands so that I can use my thumb while using the other fingers to pull the thumb into the magazine release.  The Mag Release on the magazine well is easier to operate, but still difficult.

Thanks

^ this, even if it means somehow disconnecting one or more of the buttons. I'd rather have a less ambidextrous rifle that I can use, than an ambi rifle I have to fight with.
Also, I would not be opposed to an extended/larger rear release.


-----------

Seems that the recoil mechanism could use some more protection, having it exposed to the rear of the chamber seems like a recipe for disaster. One of my failures actually lodged a case against the spring and bolt face... didn't think I'd ever get it free.


-------------

Are the lowers intended to be a .... difficult time .... attaching to the uppers? Couple people I've spoken with tend to mirror my experience of being able to get 2 pins in and then not being able to get the 3rd without considerable force.
I suspect an alignment issue that requires the lower to flex to fit, but thats just speculation.
Also, beveling the front end of the take down pins may help with insertion, especially for the rearmost.

----------------

If the gas plugs get updated, it would be nice to update with the tool adjustment slot from the 6 position version


--------------

You already addressed the gas block, but I'd like to include my 2 cents;

In its current configuration, its the worst of all options. Too small to mount anything to it except your mount and MRDS. Most people who would change barrels, I suspect, would be using other optics across the various calibers and lengths.
Its in the perfect position to burn your hand if you're using the handguard.
Because it protrudes, the aftermarket is incapable of reasonably producing a handguard that attempts to continue the receiver's top rail
It protrudes, yet we are unable to access the gas regulator through it, if it were larger it could be skeletonized an allow for top or side access to the regulator.
TLDR; Larger and skelotnized to allow for other optics mounted on it and access the gas regulator or smaller and under the handguard would be preferred

--------------------------

Someone mentioned the magazines;
It would be nice to have list of magazines that should work in the MDR, so if they're not we know something is wrong with our rifles.

-----------------------

Thanks for posting here again, its nice to hear from y'all rather than leaving us to wildly speculate and work ourselves into a tizzy.
« Last Edit: June 14, 2018, 12:45:21 PM by CabbitOne » Logged
Playro
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Robin Rothenfluh, Switzerland


« Reply #12 on: June 14, 2018, 12:47:07 PM »

Because it protrudes, the aftermarket is incapable of reasonably producing a handguard that attempts to continue the receiver's top rail
It protrudes, yet we are unable to access the gas regulator through it, if it were larger it could be skeletonized an allow for top or side access to the regulator.
TLDR; Larger and skelotnized to allow for other optics mounted on it and access the gas regulator or smaller and under the handguard would be preferred


As I stated above, there IS an aftermarket Aluminum handguard on the way (selling early July), that continues the receiver's top rail AND gives access to the gas valve. Richard Murphy has considered it all, but he's a small vendor. That's why I asked whether DT could sell them on their page.
« Last Edit: June 14, 2018, 12:48:40 PM by Playro » Logged

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Robin Rothenfluh from Switzerland
ney1
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« Reply #13 on: June 14, 2018, 12:50:44 PM »

Thanks!

I'm unaware of his website, but he's in the Facebook Group (Desert Tech MDR owners Group), where he advertised it. He's close to release & has experiences with this subject (ACR, Scar etc). He's willing to sell it via DT he told me.
Link to his profile: https://www.facebook.com/richard.karynM

Thank you, we will acquire one for evaluation.
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« Reply #14 on: June 14, 2018, 12:52:36 PM »

-Is there any way to reduce the amount of force required to actuate the Magazine Release?  Currently, I can't use the mag release near the trigger while maintaining a firing grip.  I have to shift one of my hands so that I can use my thumb while using the other fingers to pull the thumb into the magazine release.  The Mag Release on the magazine well is easier to operate, but still difficult.

Thanks

I will have to meet with our MDR engineer and get back to you on this one.
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Robin Rothenfluh, Switzerland


« Reply #15 on: June 14, 2018, 12:53:20 PM »

Great, that's good to hear! :-) Btw: thanks for your time Nick Young! A CEO that answers customer's questions is rare, but amazing
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Robin Rothenfluh from Switzerland
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« Reply #16 on: June 14, 2018, 12:57:31 PM »

Why is the height of the rail attached to the barrel higher than upper receiver rail? There is enough of a height difference that a scope mount can not cover the barrel rail in any way. I was trying to push my scope mount as far forward as I could because I didn't buy a cantilever mount, I should have!, But I could not have even a small portion of the mount cover the barrel section because of the height differences.
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« Reply #17 on: June 14, 2018, 01:03:26 PM »

I will start by saying that I am happy to hear that you decided to return to the forums ney1.

- From reading what you have posted in the second post, is the MDR is a .308 Sammi spec barrel and is not cut for 7.62 NATO, and in short, do not use 7.62 NATO in the rifle.

-From previous shot shows and other information, this rifle was being hum safe to say advertised as being a military battle rifle. With that said is there plans to have a 7.62 NATO cut chamber in the future, and if so a possible return/exchange from .308 to 7.62 NATO barrel?

-3 position gas valve,    Normal / Adverse / Suppressed,  is it normal for the MDR to function in the suppressed setting with NO SUPRESSOR used?
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CabbitOne
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« Reply #18 on: June 14, 2018, 01:12:40 PM »

Ejection Chute;

It would be nice to have a more generous (larger) ejection chute. I suspect it would reduce the number of failures early in the lifecycle of the system, as well as give more leeway when ejecting damaged(swollen/split/etc) cases.


-------------------

FDE v Black;

Could you share with us if the FDE rifles are experiencing a greater number of issues? Are there simply more of them in the wild?
From an outsiders perspective, the FDE rifles comprise the lions share of problem rifles.

------------------

MDR-C;

Is the C version/conversion still planned for some point down the road?

-----------------

Environmental Testing;

At one point there were videos that were supposed to be released illustrating the MDR's performance in various adverse conditions.
Are these still intending to be released at some point? Has the rifle changed significantly since these tests were performed?

----------------

Handguard rigidity and flexibility;

Early on there were reports of people breaking their handguard by mounting and using a bipod. Don't know if those were one off occurrences and/or user error. But, what is the handguard supposed to be capable of? Ought we be able to mount a bipod off it without fear of damage? How about a sling mount and throwing the weight of a loaded rifle + optics around?

-----------------

Chamber Fluting;

Have y'all considered and/or tested chamber fluting to reduce the force necessary for extraction? Perhaps opening up the range of cases that will function in the rifle. Granted reloaders would likely not be too happy, but I can't imagine they'd prefer stuck cases and/or ripped/damaged rims.

----------------

MDR Life Cycle;

Has your internal testing determined a life cycle for the MDR's various components?
IE when the rifle is working as intended, when will parts start needing to be replaced.
If so, could you share any of this knowledge with us so we know what to expect out of our guns.

----------------

Drop safe;

Is the rifle drop safe?
If so, what were your resting parameters?
« Last Edit: June 14, 2018, 01:31:48 PM by CabbitOne » Logged
Blackandwhiteknight
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« Reply #19 on: June 14, 2018, 01:47:07 PM »

Gentlemen,
I apologize I have been off-line for so long, we have been extremely focused on MDR production and fulfilling customer orders and we haven't communicated with our customers like we needed to.

I will try to post official Desert Tech information in this thread so please do not clutter it up.  We will post the answers to questions people are asking so if one person asks a question please don't continually ask the same question and please don't freak out at us if you don't give you a immediate answer to your question.  If anyone has questions please try to list all of your questions in bullet points as concisely as possible in one post and avoid duplication of questions so that we can easily identify them and answer them faster.

I understand that a handful of MDR rifles have run into some issues, I sincerely value everyones feedback and we want to ensure all MDR's are functioning 100% out of the gate.  I want to thank all of you who have been working closely with our warranty department to diagnose any problems that have arisen.  

First I want to give everyone assurance that very few rifles have had the issues that some of you have seen with your rifles on this forum.  But, this is a very public forum with lots of vocal customers and I can respect and appreciate that.  Unfortunately, we at DT already have egg all over our face from our continued production delays so we are already under the microscope and being overly scrutinized.  This added scrutiny and the fact that the MDR is a new breed of rifle has led many to be overly judgmental of the MDR rifle and insinuating issues that aren't real.  Others have had some legitimate issues with their rifles which is regretful.  We have stood behind the MDR 100% and we will continue to take care of every customer has any issues.  Each time an issue arises we are doing everything possible to prevent repeat issues from happening.

I appreciate everyone who has supported us and believed in us very much!

Sincerely

Nicholas Young
CEO, Desert Tech, LLC.

PS.  I will not respond to harassing or hateful posts so please keep conversations professional and courteous.



  First I just want to say thank you for returning to the forum Mr. Young.  I know it can be like the wild west with some of the comments, but some of us really enjoy the MDR and are invested in it's success. I understand you time is important but the value of communicating with your customers cannot be understated.  There has been a large amount valuable information tossed around on this forum by end users reporting their experiences.  I hope someone at Desert Tech would take the time to consider some of these observations while working on the MDR.

 I have two threads highlighting the need to reduce snags in the MDR's cycle of operation.  This arose from me experiencing frequent failures of the bolt to go into battery.  I firmly believe the MDR is a revolutionary design, but it is being hindered by manufacturing, and assembly bumps along the way.  After removing some of these snags on the cycling I have seen drastic improvement in the reliability of my MDR.

 .308 MDR ejections chute (fixed)

http://bullpupforum.com/index.php?topic=13146.0

 .308 MDR barrel extension and cycling( important)

http://bullpupforum.com/index.php?topic=13106.0


I'll just throw out three questions because I know others want to ask their questions as well.

 1. Why are the feedramps on the MDR so steep,and the magazine feed lips low in relation to the chamber? Is this a necessary design element of having multiple calibers?

 2. Why are there gas rings on the gas plug instead of just going with a close tolerance fit between the plug and block? The reason I bring this up again springs from my own experience.  I have over 100 rounds trough my MDR and while using the 3 position gas plug on normal with NATO M80 ammunition I would see an increase of gas pressure as the gun got dirty.  On a clean gun I would get little indents in the case rim, after around 100-150 rounds the damage increased significantly to the point where I have had several ripped rims.  It appears as the plug gets carbon fouled it seals around the rings and increases pressure.  I have the new 6 position plug on position 3 and it works much better.

 3. In general the piston/ plug chamber volume seems on the small side.  There's been quite a debate about the effects of this on the chamber dwell time in the MDR.  While shooting 168 gr and higher I have seem a steep increase in pressure signs and torn rims.  This seems to be a problem other users are encountering. I'm curious if this is a result of the heavier bullets on the dwell time of possibly a chamber issue? What would you recommend? 

Thank you again for you time Mr. Young.
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