MDT METAL MAGAZINES - SHORT ACTION 12 Rounders

I passed a 12 rounder throughout the past season of 2018 at my matches. Anyone who rocked an AICS compatible chassis used it for the match. Not a single bit of trouble. Go for it! At the Meaford LRSC Match on September 2018, MDT a sponsor of that match gave out 10 of these new 12 rounders. One of the CANSOFCOM snipers walked away with one. Those gunfighters never get any swag, they were most tickled!!


Cheers, Barney
 
12 Round MDT mag did not work well for me at all in a Cadex rifle.

BTW the MDT mag I used did not have a striker plate, just as the Accurate mag supplied by Cadex with the rifle did not have a striker plate.

The 12 rounder looks well made, so it's quite a disappointment that it does not work for me.

I wonder if the striker plate version would work better in a Cadex. Does anyone know?
 
I got 3 for Black Friday and they work fine in my rifles (Defiance actions, Stiller bottom metal)

I bought a couple of their shorter 10rd magazines earlier, and they did not work at all, even after I got them replaced. Unable to feed the first round when loaded with 10 rounds, simply too much tension. So I was a little hesitant with the 12rd'ers but they feed as well as my Accurate-Mags.
 
polymer mags are thicker than steel so you need to run short rounds.

You'll get more speed by loading them as long as will fit in a steel mag... as long as you have the throat for it. If you don't, then shoot off 1000 rounds, then you will.
 
I've run the 12 rounders with and without backer plates with .308 and 6 Creedmoor in a couple R700s (with notched feed ramps), a Defiance Elite and a ARC Nucleus sitting in MDT ACCs, ESSs and a KRG Bravo with zero issues.
 
I am a little confused on how they didn't work in your Cadex @Maple57? Did the rounds get hung up under the action? Did the magazine not latch in? Did your rounds not fit in the magazine?

I have run a ton of the 12 rounders now in 6.5 CM, 308 Win and now the 6 Dasher with a spacer kit. All have been through MDT chassis and friends KRG's, McMillan's and XLR's. If you're having an issue with one of the mags, a quick feedlip tweak, mag latch tweak or replacement spring/follower will solve your issues ;)
 
Kudu said:
I am a little confused on how they didn't work in your Cadex @Maple57? Did the rounds get hung up under the action? Did the magazine not latch in? Did your rounds not fit in the magazine?

I have run a ton of the 12 rounders now in 6.5 CM, 308 Win and now the 6 Dasher with a spacer kit. All have been through MDT chassis and friends KRG's, McMillan's and XLR's. If you're having an issue with one of the mags, a quick feedlip tweak, mag latch tweak or replacement spring/follower will solve your issues ;)
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The rifle is CDX-30 Guardian TAC chambered in 308.

The rounds tested were Hornady Steel Match and some of my own hand loads. Both FTF'ed the same way.

All were seated short enough to operate in the Accurate Mag with no stripper plate which came with the rifle.

The rounds also were short enough to fit nicely in the MDT 12 round mag with no stripper plate.

The exact nature as to why they failed to feed is hard to say, but I will look into it further.

I did have a camera rolling at the time and the FTF's were recorded, (several times BTW) but the camera was not directed closely on the ejection port, so I'm not sure what that video will reveal.

If I recall, the bolt began to move forward, maybe an inch and then jammed. Then I retracted the bolt and fiddled a bit and sometimes it would feed, sometimes I would have to remove the round and try again.

Next time, I'll put a camera right on the ejection port and get a good video of what is going on.

I've had zero feed issues with any ammo with the mag supplied by Cadex with the rifle.

I'd really like to be able to use the 12 round mag if I can sort this out.
 
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Maple57 said:
The rifle is CDX-30 Guardian TAC chambered in 308.

The rounds tested were Hornady Steel Match and some of my own hand loads. Both FTF'ed the same way.

All were seated short enough to operate in the Accurate Mag with no stripper plate which came with the rifle.

The rounds also were short enough to fit nicely in the MDT 12 round mag with no stripper plate.

The exact nature as to why they failed to feed is hard to say, but I will look into it further.

I did have a camera rolling at the time and the FTF's were recorded, (several times BTW) but the camera was not directed closely on the ejection port, so I'm not sure what that video will reveal.

If I recall, the bolt began to move forward, maybe an inch and then jammed. Then I retracted the bolt and fiddled a bit and sometimes it would feed, sometimes I would have to remove the round and try again.

Next time, I'll put a camera right on the ejection port and get a good video of what is going on.

I've had zero feed issues with any ammo with the mag supplied by Cadex with the rifle.

I'd really like to be able to use the 12 round mag if I can sort this out.
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The magazine sits a little lower on a CDX-30 because of the 3-lug design. The MDT 12 round mags worked in mine, but if the one you have are having bolt-overs (cartridge rim drops down when bullet point hits feed ramp) , open the lips up to around 0.425" front and rear.
 
rgv said:
The magazine sits a little lower on a CDX-30 because of the 3-lug design. The MDT 12 round mags worked in mine, but if the one you have are having bolt-overs (cartridge rim drops down when bullet point hits feed ramp) , open the lips up to around 0.425" front and rear.
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That would be the culprit right there. You're running into much the same issues that the Ruger American's have @Maple57 and @RGV is right, opening up your feelips will help get the rounds up higher. I've heard that Cadex manually modifies some of their accurate mags to work better in their actions, so that would explain why they feed in your chassis and the MDT's may not.
 
So I confirmed with my Cadex the bolt is in fact riding over the rounds as they come out of the mag.

I did some measuring on some of the metal AI pattern 308 mags I have...

The distance between the feed lips is as follows...

............................................................Width at back of mag lip....... Width at front of mag lip
Accurate Mag supplied with Cadex rifle..... 0.416 .................................. 0.417
MDT 12 round metal mag ...................... 0.404 ....................................0.393
Ruger Accurate mag ............................. 0.419 ................................... 0.400
Real AI mag # 1 .................................. 0.380 ................................... 0.395
Real AI mag # 2 ................................. 0.376 .................................. 0.395

Interestingly the real AI mags have the closest feed lips.... and they are wider at the front to create a little "up" attitude... I have not tried them yet in the Cadex... I feel like a dummy as I type this BTW... I should have tested all the mags. But they have always worked in other rifles.

Anyway... I did as RGV suggested above ^^ to widen the feed lips on the MDT 12 round metal mag.

I put a couple paint stir sticks between the lips and jammed a screwdriver in between. I gave it a little twist and tried a few times, but I got it.

The lips are now 0.417 apart and rounds seem to feed just fine so far. I hope they prove out well in time as the MDT 12 rounder would be my fist choice for the extra capacity and ease of loading 10 rounds.

So thank you RGV for the suggestion.

BTW the Ruger accurate mag is narrower at the front of the feed lips, and that mag was a fail in the RPR. Rounds would get stuck between the feed lips like they were too far apart... and I could not drive the rounds hard enough to feed them. I'm sure I'll have to give that mag a little attitude adjustment as well.

If there's anything can draw from this is the feed lips should be wider at the front than at the back. If the feed lips are closer at the front, then the rounds can bind or misfeed.
 
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