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Problem MG2

Posted: Sat Apr 11, 2015 1:05 am
by CamelNL
A few monthes ago i bought myself a new Matchguns MG2. It worked flawless and i can shoot realy well with it but after a few monthes its is bugging me a bit.

Yesterday he refused to extract a cartridge which causes to double feed a cartridge. Sometimes he extracts not enough ; then a empty cartridge is stuck in the frame. You guys have any idea what it can be?

Re: Problem MG2

Posted: Sat Apr 11, 2015 1:29 am
by SamEEE
Extractor spring could be the issue, or the extractor itself.

Careful of the annodised finish on the Matchguns MG-2.
From my experience they can only take so many tears before corrosion sets in.

Re: Problem MG2

Posted: Sat Apr 11, 2015 1:34 am
by shaky hands
It could be a lot of things: a bad extractor, for example (you probably have cleaned your pistol thoroughly to make sure it is not gummed up). Some things could help with extraction, such as using a weaker recoil spring or polishing the chamber. Small-bore semi-autos are often finicky about ammo, every make and model usually has ammo that it likes more and that it likes less.

Re: Problem MG2

Posted: Sat Apr 11, 2015 1:46 am
by CamelNL
I disassembled the gun totally and cleaned it. It was not really dirty but also not clean. It was the first time i disassembled it. I hope its solved now otherwise i will bring it to the shop for a repair.

Re: Problem MG2

Posted: Sat Apr 11, 2015 8:18 am
by Gwhite
The vast majority of extraction problems I've seen are from a dirty chamber. The chamber is larger than the bore, and a .22 bore brush (especially one that has been down a barrel a few times) will often not do a good job of getting fouling out of the chamber. You can either keep a new .22 brush handy that you use only on the chamber (so the bristles don't get mashed down or worn), or use a .25 caliber brush. Some brands of .22 brush will just slip right through the chamber even when brand new. I've made up a bunch of these for the team I help coach:

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On many semi-autos, you can use these without disassembling the pistol (although it might be difficult on an MG-2). To get rid of the crud you've loosened up, we use a "Patch Worm" style pull through cord:

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This process and a little oil can quickly make a world of difference in the middle of a match.

Re: Problem MG2

Posted: Sat Apr 11, 2015 9:41 am
by shaky hands
Does the chamber really require that much bronze brushing? The bore gets lead deposits from the bullet rubbing against the rifling, but the chamber's crud is much softer and is mostly a powder residue.

Re: Problem MG2

Posted: Sat Apr 11, 2015 11:17 am
by Gwhite
The stuff in the chamber can vary a lot with ammo. Some of it is mixed with lube, and it gets both baked & hammered into place. If you are cleaning with a worn or undersized brush, it also builds up over time.

What I can tell you is that a quick chamber brushing on the line will often take a pistol that is malfunctioning constantly and return it to reliable operation. When I first started coaching my college team, we had a Pardini PGP-75 free pistol that had been set aside (possibly for years) because of constant extraction failures. I gave the chamber a thorough brushing with a 25 caliber brush, and it's been fine ever since, with only an occasional light scrub.

I am trying to use up some Aguila Subsonic in my own Pardini SP New. Previous batches worked fine in this pistol, but this lot is nothing but trouble. It burns really dirty, with a lot of unburned powder. Because the powder it isn't burning well, it also has weak recoil. About 20 rounds after a good cleaning, it will fail to come back far enough to pick up the 2nd round in the magazine (when slide drag is at its maximum), or fail to extract. I've cut about an inch off the recoil spring, and it will go about 80 rounds without issues now. When it messes up, the chamber brush routine will keep it happy for another 60 or more.

If everything else in the pistol is polished & lubricated properly, the drag from the build up of crud in the chamber won't be an issue for quite a few rounds. If something is marginal, the added drag from a dirty chamber can push it over the edge. Try dropping a round into your chamber after you've fired a hundred rounds. Unless you are very lucky (or have an oversized chamber), it will barely go in under its own weight, and may take a bit of a push to chamber. Extracting it will also take a (hopefully tiny) bit of force. That's drag that isn't there when the chamber is clean.

Many .22's will work just fine with no extractor at all, IF the chamber is nice & clean. The slide doesn't PULL the case out, the case pushes the slide back. That said, a good grip from an extractor may be required for decent ejection. However, if the case is frozen in the chamber with crud, it's not going anywhere. We occasionally have to use a rod to get cases out of pistols. When the student is asked when was the last time the pistol was cleaned, the answer tend to be a bit vague...

Re: Problem MG2

Posted: Sat Apr 25, 2015 11:07 am
by shaky hands
OK, Gwhite, I want to try your .25 brush and see if it can make Aguila work in my S&W41. I got the brush. Any tips on how to bend it without messing up the bristles?

Re: Problem MG2

Posted: Sun Apr 26, 2015 3:57 pm
by Gwhite
Because I make them up by the dozen, I made a bending tool on a lathe out of 1/2" aluminum rod stock. They are bored out to the right depth to get the bend in the right place. However, 1/4" ID straight tubing will work fine. The telescoping hobby shop brass tube should be good. Two short pieces will keep the bristle in good shape.

Re: Problem MG2

Posted: Sun Apr 26, 2015 5:30 pm
by shaky hands
Thank you. I wonder whether, given that removing the barrel on Smith 41 takes only a couple of seconds, putting a few layers of electric tape around the brush up to the length of the chamber, thick enough to stop the brush from going in any further, would be sufficient. I would then use the regular cleaning rod to push it in. You could then, after spending the top end of the brush, move the tape back and use the middle part of the brush, and so on. The brush is long enough to utilize it three times at least.

Re: Problem MG2

Posted: Sun Apr 26, 2015 8:59 pm
by Gwhite
That might work fine on a 41. We shoot Benelli MP90's & 95's, and getting access to the chamber with a rod requires a lot more disassembly.