Tuning MDT 6BR Mags

Slate264

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  • Jun 19, 2019
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    Looking for recommendations how tune MDT 6br mags. Bought 2 mags and both not functioning properly. Every 7/8 round nose dives when either running the bolt or doing it by hand. impact action and mpa chassis. If you had a similar issue and fixed pls let me know how. Thank you
    99B83636-2CEF-481F-9DDB-B96D0C48F32E.png
     

    spife7980

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    Feb 10, 2017
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    Can’t tell what the failure is by looking at the outside of a mag. Is the follower sticking down inside the mag?

    Does every 7/8 mean it fails on round 7 or 8 out of 10? Or just every so often with no relation to the exact round out of the mag? Aka, if you don’t fill it up that full will they still fail or is it o my those rounds at that point? Tried stretching the spring out of the follower is sticking? Need to sand the follower a smidge?

    Lots to know that we don’t.
     

    Dschapp44

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  • Oct 15, 2018
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    I ran into a similar problem. Make sure there’s about .050-.060 minimum from the front of the round the the of the magazine.

    also putting a screw thru the bottom while and pinning the spring to the back spacer did wonders. Both were recommended to me by Keith Baker
     
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    Slate264

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  • Jun 19, 2019
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    Can’t tell what the failure is by looking at the outside of a mag. Is the follower sticking down inside the mag?

    Does every 7/8 mean it fails on round 7 or 8 out of 10? Or just every so often with no relation to the exact round out of the mag? Aka, if you don’t fill it up that full will they still fail or is it o my those rounds at that point? Tried stretching the spring out of the follower is sticking? Need to sand the follower a smidge?

    Lots to know that we don’t.
    7th or 8th round dives when I load 11 or 12 in the mag. Haven’t tried just 3 or 4 in the and see if they dive too. Will check if the follower is sticking inside the mag as well. Never ran br family cartridges before so this magazine stuff is new to me
     

    Slate264

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  • Jun 19, 2019
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    I ran into a similar problem. Make sure there’s about .050-.060 minimum from the front of the round the the of the magazine.

    also putting a screw thru the bottom while and pinning the spring to the back spacer did wonders. Both were recommended to me by Keith Baker
    Looks like there is plenty of clearance from the tip to the mag.
    Can you pls explain the second step in more details
     
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    drwood96

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  • Sep 16, 2017
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    IMO, the back of your feed lips are too wide. You normally want back closer then the front. The MPA feed lip tool or pliers work to adjust them. These are stamped metal part and not every one come out prefect.
     
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    Dschapp44

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  • Oct 15, 2018
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    Looks like there is plenty of clearance from the tip to the mag.
    Can you pls explain the second step in more details
    After you taken the baseplate off and are reinstalling don’t push all the way closed. Just enough so the hole in the bottom of the mag is inside the mag body and then install the screw as shown in pictures and finish installing baseplate all the way on.

    second picture is case at the top of mag and how it sits on the feed lips. Those are non adjusted from the factory feed lips
     

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    Birddog6424

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    @Birddog6424 - yo dude, wasn't this the same issue you were talking to Pat and I about at the .22 match?
    This one is the exact opposite. His nose is dropping into the mag and sticking there.

    My round feeds forward, and as soon as it clears the feedlips, the base of the round drops into the magazine and the nose hits the barrel instead of feeding into the chamber. Its a pain in the ass..
     
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    TwistedOneinSeven

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    Mar 24, 2020
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    Looking for recommendations how tune MDT 6br mags. .
    I'm using MPA Chassis, Terminus Zeus actions, MDT "BR" mags and AI AICS with MDT BR/Dasher Follower kits;
    I think MDT BR mags need a "stronger" follower spring.
    No comparison to AICS MDT (actually PVA I think) BR Follower Kit spring as far as nose-up pressure on follower and rounds.

    Tip I was given that works well is to always put some graphite powder in new mags to lubricate follower travel - makes a huge difference in follower binding in my experience.
    Also, check COAL. MDT lists possible of appx 2.500" but if my cartridges are near COAL 2.500" about 7/8th round nose dives as mentioned in OP
     
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    Slate264

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  • Jun 19, 2019
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    After you taken the baseplate off and are reinstalling don’t push all the way closed. Just enough so the hole in the bottom of the mag is inside the mag body and then install the screw as shown in pictures and finish installing baseplate all the way on.

    second picture is case at the top of mag and how it sits on the feed lips. Those are non adjusted from the factory feed lips
    Thanks for detailed explanation, I’ll give it a shot