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Author Topic: New Gas Valve available for purchase  (Read 11852 times)
Potss
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« Reply #120 on: June 09, 2018, 08:55:35 PM »

I smoothed the sharp edge on the shell holder in the ejection chute almost right away when I couldn't eject cases by hand.

Ejection problems are one of the few issues I haven't had ever since.

Do you believe this is something that you *should* have had to do so that it would be reliable or that it should have come from the factory with it already done?  If this was a used Hi-Point carbine, I wouldn't mind taking a Dremel to it, but it's a $2500 rifle from what has been known as a premium manufacturer; this should have been right when it was taken from the box.

That little rant over, I have to wonder who much pressure from the public played in DT releasing it before the bugs were completely worked out.


It clearly had little to no effect.  They were more than happy to sit around and take free loans till competition started to emerge and eat market share/potential customers.

If they'd done 1/10th of the testing they'd claimed to do (and you know, acted on the results), then the rifle would be in MUCH better shape than it is now.
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thehun
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« Reply #121 on: June 09, 2018, 10:24:20 PM »

^^Agreed.

Before you know it...all these little DIY engineering work will turn into a MDR tune shop somewhere and make a buck... Evil Evil Evil
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Blackandwhiteknight
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« Reply #122 on: June 09, 2018, 11:41:45 PM »

or for that matter, eject a live round through the chute by manually cycling the action back on an empty mag (or no mag) and letting the bolt fly forward, there are issues far beyond a flaky gas plug.

lol...you lost me with this one kurt.  why wouldn't it eject a live round on an empty or no mag when manually cycled?  all other guns do it.  rdb with live round will eject the live round downward.  fs2000 will eject live round out the front chute....etc...  and, as designed, the mdr ejects the live round out the ejection chute on an empty or no mag when manually cycled.

now on an empty mag the live round will slide to the chute and remain until the bolt is released...subsequently flying forward once done.

Because when the action is cycled, the tip of the bullet nosedives back toward the interior of the rifle and misses the opening, only to get caught with the cartridge pushed forward enough that the bullet tip is trapped on the inside side of the hatch frame and the bolt/bolt carrier then proceeds  to crush the side of the cartridge facing the inside of the rifle.  There was at least one picture of this floating around recently that showed the cartridge held by the spring in the chute, but pushed forward enough that the bullet was behind the chute frame.



If this is happening it is operator induced.  This topic has been brought up several times.  The scissor mechanism requires a certain amount of force to correctly push the cartridge out to the ejection chute.  If you ride the charging handle you will induce a malfunction every time.  Never had a problem ejecting live rounds after I realized this.
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Blackandwhiteknight
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« Reply #123 on: June 09, 2018, 11:52:01 PM »

  Hit the range today with the new 6 position gas plug.  Man what a difference. Put on number 3 and left it there.  I ran 100 rounds through it at everything from a slow fire, to mag dump speed.  Not a single hiccup.  Looking closely at the brass the extractor marks were so light I had a hard time finding some of them.  So i confirmed my earlier hypothesis, this is not an upgrade, its mandatory.  With over 1K rounds I was still getting case damage with M80, and torn rims with M118LR using the sleeved 3 position plug.  Going to stop messing with it for awhile and reset the "rounds fired since malfunction clock". Lets see how it goes.  Over all a great time shooting the MDR today.  Ran reliably and pulled 1 MOA easily.

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thehun
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« Reply #124 on: June 09, 2018, 11:57:07 PM »

Let's hope it keeps ticking away. Great to hear.
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Box
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« Reply #125 on: June 10, 2018, 12:38:36 AM »

  Hit the range today with the new 6 position gas plug.  Man what a difference. Put on number 3 and left it there.  I ran 100 rounds through it at everything from a slow fire, to mag dump speed.  Not a single hiccup.  Looking closely at the brass the extractor marks were so light I had a hard time finding some of them.  So i confirmed my earlier hypothesis, this is not an upgrade, its mandatory.  With over 1K rounds I was still getting case damage with M80, and torn rims with M118LR using the sleeved 3 position plug.  Going to stop messing with it for awhile and reset the "rounds fired since malfunction clock". Lets see how it goes.  Over all a great time shooting the MDR today.  Ran reliably and pulled 1 MOA easily.

That's some much needed good news.  I'm curious how it'll do now with various types of ammo.
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kfeltenberger
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« Reply #126 on: June 10, 2018, 01:38:51 AM »

If this is happening it is operator induced.  This topic has been brought up several times.  The scissor mechanism requires a certain amount of force to correctly push the cartridge out to the ejection chute.  If you ride the charging handle you will induce a malfunction every time.  Never had a problem ejecting live rounds after I realized this.

I'm glad you don't have this issue, but that doesn't belay the fact that some do/have had the issue.  The incident I refer to was not caused by "operator error"...
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Kurt
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« Reply #127 on: June 10, 2018, 02:26:40 AM »

Can you buy the shell holder and if so for how much $?

I ask because if it cheap to replace then having a spare one to polish while being able to put the original unmolested one back in is what I would recommend. 

It sounds like an opportunity for a small parts fabricator to offer a polished after market replacement. 
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Re: MDR Group Buy - official BPF list!
ę Reply #360 on: January 04, 2015, 05:29:50 AM Ľ
(Still waiting patiently on an FDE...)
newguy2k3
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« Reply #128 on: June 10, 2018, 08:47:18 AM »

I literally took about 30 seconds with a knife sharpening stone to just dull the sharp edge and it fixed all my issue. The difference in the amount of force it took to snap a casing into the chute before and after was significant.
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Zeiram3f
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« Reply #129 on: June 10, 2018, 09:26:28 AM »

Care to share a photo of your work? I know there's not a 'before and after', but I'd at least like to see the after and compare it to my before.

Thanks in advance  Cool
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newguy2k3
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« Reply #130 on: June 10, 2018, 10:10:23 AM »

Not much material removed at all. Turned the knife edge into a ramp pretty much.


* image.jpg (2065.29 KB, 4032x3024 - viewed 251 times.)
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Blackandwhiteknight
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« Reply #131 on: June 10, 2018, 12:17:35 PM »

Not much material removed at all. Turned the knife edge into a ramp pretty much.

 Good work Newguys2k3.  Glad I'm not the only one who noticed that.  Looks like the piece is held in by a captive pin/spring at the back.  Watching them install it they just push it in from the outside, which would support this theory. Its at 1:48  Video is great at .25 speed.
https://youtu.be/xgwj3OG3Nag
 Just need something to pull those pins back a bit and it should pop out.  It would be really easy to knock off the sharp edges with some fine abrasive, then polish it up, pop it back in and you are good to go.
  Thinking this is a major issue with the current guns.  You could reduce drag on the system at two points by removing the catch point going into, and as it is pushed out of the chute.   Would change the chute to a nice hug and push, instead of a chew and rip. Cheesy
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Articlion
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« Reply #132 on: June 10, 2018, 12:52:04 PM »

I literally took about 30 seconds with a knife sharpening stone to just dull the sharp edge and it fixed all my issue. The difference in the amount of force it took to snap a casing into the chute before and after was significant.
Well thatís  1 voided warranty and 1 less riffle dt will have to worry about
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newguy2k3
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« Reply #133 on: June 10, 2018, 01:16:00 PM »

I literally took about 30 seconds with a knife sharpening stone to just dull the sharp edge and it fixed all my issue. The difference in the amount of force it took to snap a casing into the chute before and after was significant.
Well thatís  1 voided warranty and 1 less riffle dt will have to worry about

Frankly I don't give a damn. The gun went back to DT within days of me receiving it with explicit explanation of the issues it had, what worked, what didn't. Guess what. It still didn't work right when I got it back. I have little patience for incompetence. So far the little things I have done have only made the rifle work more like it should have in the first place.

If you're completely helpless, lack tools and are not mechanically competent then by all means send any little item you have issues with back to the manufacturer and hope they handle the issue.
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newguy2k3
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« Reply #134 on: June 10, 2018, 01:17:50 PM »

Not much material removed at all. Turned the knife edge into a ramp pretty much.

 Good work Newguys2k3.  Glad I'm not the only one who noticed that.  Looks like the piece is held in by a captive pin/spring at the back.  Watching them install it they just push it in from the outside, which would support this theory. Its at 1:48  Video is great at .25 speed.
https://youtu.be/xgwj3OG3Nag
 Just need something to pull those pins back a bit and it should pop out.  It would be really easy to knock off the sharp edges with some fine abrasive, then polish it up, pop it back in and you are good to go.
  Thinking this is a major issue with the current guns.  You could reduce drag on the system at two points by removing the catch point going into, and as it is pushed out of the chute.   Would change the chute to a nice hug and push, instead of a chew and rip. Cheesy


I didn't even take it out. Just a few swipes with a diamond stone was all it took.

If someone wanted quantifiable answers I suppose you could measure the amount of force it takes to snap a case into and out of the ejection chute in stock form and then with the edge smoothed out.
« Last Edit: June 10, 2018, 01:25:54 PM by newguy2k3 » Logged
GoShort
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« Reply #135 on: June 10, 2018, 02:25:29 PM »

New gas block measurements best i can get.
I did not even attempt to measure the gas ports
Inckuding a pic you can see the ledge inside the gas chamber.

Sent from my Nexus 5X using Tapatalk
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newguy2k3
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« Reply #136 on: June 10, 2018, 03:51:16 PM »

Copy and paste from the MDR owners group on Facebook.

1-0.015"
2-0.026"
  (S-0.030")
3-0.037"
4-0.041" (also Normal)
5-0.044"
6-0.049" (also Adverse)
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AF Gunner
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« Reply #137 on: June 12, 2018, 10:22:08 AM »

The measurements above are mine and I used a pin gauge set to check.

I also used a stone to knock down the sharp edges on the ejection chute paw. It does less damage to the brass now. there are still few area of the paw I would like to debur but I need to take the paw out of the chute to get to them. I also took a fired steel case and worked it by hand through the chute several hundred times trying to wear down any other areas I missed. Not sure if it did anything but I did it anyway.

Gunner
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newguy2k3
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« Reply #138 on: June 12, 2018, 09:11:28 PM »

Range report with the new gas valve.

40.5gr Tac, 175smk, LC 1x brass, #34 primer. Surefire Sps-300

Started off on #2.
One round, locked back.
2 rounds, fed and locked back.
Switched to #1
One round, locked back
2 rounds, fed and locked back
Loaded 5 and had stovepipish failure with carrier not moving rearward enough to eject spent case.
Switched back to setting 2 and fired 4 remaining.
Loaded the remaining of the 20rds from that mag.
Made it to #18 and the ejector panel popped loose. Never had that happen before and it jammed the case in between the bolt and charging mechanism. Had to dig it out with a screwdriver. It would bind up the charging mechanism and the tension on the case was never relieved. Cleared that and round 19 stuck in the chamber. I didn't have a cleaning rod with me because I thought I was past that but apparently not. It popped out easily with the weight of the rod when I got home.

I hadn't had any stuck case failures in 80 or 100 rounds so this was odd. I was hoping I could get to the bottom of the dead trigger issues I had been having though.

It hasn't been out of the safe in 2-3 months. Probably be another 2-3 before I feel like being disappointed again.
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Blackandwhiteknight
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« Reply #139 on: June 12, 2018, 11:56:53 PM »

Range report with the new gas valve.

40.5gr Tac, 175smk, LC 1x brass, #34 primer. Surefire Sps-300

Started off on #2.
One round, locked back.
2 rounds, fed and locked back.
Switched to #1
One round, locked back
2 rounds, fed and locked back
Loaded 5 and had stovepipish failure with carrier not moving rearward enough to eject spent case.
Switched back to setting 2 and fired 4 remaining.
Loaded the remaining of the 20rds from that mag.
Made it to #18 and the ejector panel popped loose. Never had that happen before and it jammed the case in between the bolt and charging mechanism. Had to dig it out with a screwdriver. It would bind up the charging mechanism and the tension on the case was never relieved. Cleared that and round 19 stuck in the chamber. I didn't have a cleaning rod with me because I thought I was past that but apparently not. It popped out easily with the weight of the rod when I got home.

I hadn't had any stuck case failures in 80 or 100 rounds so this was odd. I was hoping I could get to the bottom of the dead trigger issues I had been having though.

It hasn't been out of the safe in 2-3 months. Probably be another 2-3 before I feel like being disappointed again.


Unless you are running a suppressor the #3 setting is what you want. I've found it works great on mine.  If you are getting a dead trigger I would start looking real hard to see if the bolt is going all the way into battery.

 A quick way to do a in battery check is to look for the little half round tab on the bolt in this window.  I should look like this if its in battery.



 If you are having issues I would look at your barrel extension and feed ramps first.  I had a really bad bur on my feedramps that was causing a lot of drag.  I also just posted a thread about cleaning up the ejection chute which will help cut down on drag on the bolt.  You may want to try some light bullets and see how they do.   Mine doesn't like the heavier stuff.
« Last Edit: June 13, 2018, 10:15:10 PM by Blackandwhiteknight » Logged
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