Tuning M10 magazines

[JCcypress]

Is there a source for information on tuning/tweaking M10 magazines?

I have tried the UT search feature and google to little avail.

Thank you.

 

[Deerhurst]

I've never had to do anything to my M10 mags. What mags are you using? What issues?

 

[LawBob]

Is there a source for information on tuning/tweaking M10 magazines?

I have tried the UT search feature and google to little avail.

Thank you.

The most really you could do with the mags is put a little oil or preferably non oil lubricant inside, and use a dowel to push the follower up and down 50-100x

That would wear and smooth any burrs or sticky points inside

But the mags are so thick of you are having a problem it’s more likely your gun

If you are using great gun mags with a modified grease gun mag catch, your mags aren’t sitting at the correct height in your gun: change the mag catch to a gg mag catch (or a lage 2 stage).

If you are doing that and get fail to feeds, it’s possible the feed ramp needs a little adjusting. Need snap caps but watch the snap cap ramp
Up into the barrel.

There’s a metal bar with a cut out that allows the center part to be adjusted forward or back a little. That’s the “feed ramp” on the lower just behind the fire control group. To properly adjust it, you’ll use a crescent wrench but will need to remove the fire control unit out to get the best purchase on the adjustable “tab” iirc.

You can keep adjusting it without the FCU by manually using the bolt handle to feed more snap caps (after you put the upper back on). When it looks good re install the fcu.

The tab needs to bump the bullet just enough to enter the chamber just so. It doesn’t have to center the bullet to the chamber, just enough that the edge of the bullet wants to enter.

I had that prob w my lage upper. The barrel “seemed” maybe 1/16” closer to the mags but with the tab adjusted to encourage the rounds just a little I’ve never had a problem since.

 

[timkel]

45acp or 9mm?

 

[JCcypress]

M10 9mm

My gun came with four mags from previous owner (I need to check for manufacturer marks). One of them works flawlessly, the other 3 are prone to misfeeds.

I also purchased four of the RPB mags from FTF, and they seem to "over-insert" such that the bolt cannot close at all.

I have some experimenting to do, as I am using a Lage upper and a Lage dual mag catch, and I have not cycled through all of the mags yet.

Thank you for the tips on the feed ramp!

 

[timkel]

The M10 9mm RPB mags from FTF are very good mags. As new the bolt was hitting/rubbing the feed lips. So I cleaned up the feed lip area with a dremel on each mag.
See cleaned up feed lips in pic.

 

[Deerhurst]

I was not aware the dual mag catch did anything for the 9mm. I thought it was M10/45 only to allow the use of unmodified grease gun mags.

Is the tab on the catch at the same location as the original?

 

[JCcypress]

I was not aware the dual mag catch did anything for the 9mm. I thought it was M10/45 only to allow the use of unmodified grease gun mags.

Is the tab on the catch at the same location as the original?

Thank you. I suspected the mag catch could be part of the issue. The mag catches are listed in the M10/9 section on Lage website. I understood the description to include standard MAC mags, but I am admittedly very new to MACs, so I may have misunderstood. I can compare the original and the aftermarket this evening.

 

[JCcypress]

The M10 9mm RPB mags from FTF are very good mags. As new the bolt was hitting/rubbing the feed lips. So I cleaned up the feed lip area with a dremel on each mag.
See cleaned up feed lips in pic.

Did you have to remove any significant amount of material or just polish?

 

[timkel]

I used a cutting wheel to remove any metal that was blocking the bolt.
I used a sanding drum to remove burrs sharp edges, ect.
Test mag function with dummy cartridges.
Now ready for range testing.

 

[LawBob]

45acp or 9mm?

Well I don’t know why I assumed he meant 45

 

[LawBob]

Thank you. I suspected the mag catch could be part of the issue. The mag catches are listed in the M10/9 section on Lage website. I understood the description to include standard MAC mags, but I am admittedly very new to MACs, so I may have misunderstood. I can compare the original and the aftermarket this evening.

Also not a 45 mag catch doesn’t work on a 9 mag

 

[cherenkov]

I would think springs are a factor - If the mag can't time the pickup of the next round in proper time (weak spring) it could lead to jams.

 

[Gaujo]

Are you shooting a known good upper?