Hello!
I found an old thread describing a similar problem (viewtopic.php?t=56519) but could not really glean the required insight from it. I have recently bought an MG4 (I have shot it four times so far). Not that rarely, maybe once every ten shots, it will "double up". The second release happens so quickly that it feels like an extra-long recoil: there is seemingly no delay at all. It has never fired a third shot.
For safety and sanity I started loading one cartridge at a time. Every ten shots or so, I am noticing when I reload the hammer having dropped. Whatever causes it seems at least to be consistent whether there is another cartridge or not.
I have watched some YouTube videos on how the trigger works and have read the few sentences offered by the manual. The reseller may have tuned the trigger before delivery and I suspect that some setting is too "tight", but I am not sure which one. Any tips on how to go about investigating the issue would be greatly appreciated!
MG4 double fire
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Re: MG4 double fire
If the MG2 uses the same trigger design as the MG4, there is an excellent video on setting up the trigger:
https://www.youtube.com/watch?v=x8t-aZfyx3A
Once you get the grip off and watch the video so you understand how it works, you should be able to see if the engagement between the release levers is marginal. It is also possible that the engagement between the secondary release lever and the hammer is marginal, in which case it will need to be repaired by an experienced gunsmith or sent back to the factory. There is no adjustment for that, other than by replacing the hammer, and stoning it to set the engagement.
It's been a while since I worked on mine, but to increase the engagement between the primary & secondary release levers, but I think you need to turn screw #4 (the outer one) clockwise. I don't have one in front of me, but I think there is a locking screw on the side that needs to be loosened first. To get access to the screw, I used to take the two trigger springs out. I've learned that a ball-end hex key allows you to make small adjustments without doing that. It is also helpful to put some kind of a small mark on the end of the screw so you can keep track of how much you rotate it. I have a fine-point silver paint pen that I use for that.
https://www.youtube.com/watch?v=x8t-aZfyx3A
Once you get the grip off and watch the video so you understand how it works, you should be able to see if the engagement between the release levers is marginal. It is also possible that the engagement between the secondary release lever and the hammer is marginal, in which case it will need to be repaired by an experienced gunsmith or sent back to the factory. There is no adjustment for that, other than by replacing the hammer, and stoning it to set the engagement.
It's been a while since I worked on mine, but to increase the engagement between the primary & secondary release levers, but I think you need to turn screw #4 (the outer one) clockwise. I don't have one in front of me, but I think there is a locking screw on the side that needs to be loosened first. To get access to the screw, I used to take the two trigger springs out. I've learned that a ball-end hex key allows you to make small adjustments without doing that. It is also helpful to put some kind of a small mark on the end of the screw so you can keep track of how much you rotate it. I have a fine-point silver paint pen that I use for that.
Re: MG4 double fire
Now that I've had my morning caffeine and thinking some more about it, I'm not convinced it's a trigger adjustment issue. The only time I've had doubling in my MG2's is when I've had light recoiling ammo, or my recoil springs were too stiff. If the slide doesn't come back far enough to cock the hammer & release levers, you can get "hammer follow". The hammer just rides the back of the slide as it goes forward, and it can push on the firing hard enough to fire the next round.
The MG2 can come with one of three different strength recoil springs. It may be that your springs are a bit too stiff for your ammo. I'd contact the importer and see if you can get a pair of the softest springs. The quickest fix may be to try some different ammo. See if you can get some that has a published velocity a bit higher than what you are shooting. I'd also ask around and see what ammo other MG4 owners are shooting.
The MG2 can come with one of three different strength recoil springs. It may be that your springs are a bit too stiff for your ammo. I'd contact the importer and see if you can get a pair of the softest springs. The quickest fix may be to try some different ammo. See if you can get some that has a published velocity a bit higher than what you are shooting. I'd also ask around and see what ammo other MG4 owners are shooting.
Re: MG4 double fire
Thank you, Gwhite, for your elaborate answer!
The MG reseller in my country of residence has unfortunately lost their key MG proponent and decided to stop selling them, and they have recently lost another employee that has worked on them, so while I will say that they have attempted to help as much as they can, their knowledge is fairly limited. During a conversation with them, the person I spoke to speculated that it could be related to the "disconnector engagement" screw (#5). In the manual, it warns that if I turn it too much the trigger will not release. If I am reading between the lines, that screw seems to have something to do with how much forward movement of the trigger is required for it to reset. I guess what was said during the phone call was that perhaps it is the case that that adjustment is too tight, and the trigger is reset basically during the recoil.
Another thing that we speculated about was that it was related to screw #4, i.e. what you said above about the two release levers. There is a bit of noticeable creep (when one pays attention) but not too much.
The third thing you mentioned is interesting: .32 S&W long WC is not trivial to come by, and I managed to pick up a single box (50) of Fiocchi, and then I have managed to get ahold of a bunch of Sellier & Bellot. I also have a few Lapua (the 83-grain ones, I think). I have not tested the Lapua yet, I do not think I got a single double-fire with the Fiocchi (and I have no more of them at the moment). This theory does make sense: the slide comes back, the hammer comes after and the firing pin strikes the cap as the cartridge comes to a stop: boom. I will investigate, but it will take a bit of time!
The manual lists these springs as "4014 bolt spring" (for the MG2(E) as 2014), but there is but a single variant of it. Is that some kind of special order? I can contact MatchGuns directly; I have ordered directly from Italy before.
The MG reseller in my country of residence has unfortunately lost their key MG proponent and decided to stop selling them, and they have recently lost another employee that has worked on them, so while I will say that they have attempted to help as much as they can, their knowledge is fairly limited. During a conversation with them, the person I spoke to speculated that it could be related to the "disconnector engagement" screw (#5). In the manual, it warns that if I turn it too much the trigger will not release. If I am reading between the lines, that screw seems to have something to do with how much forward movement of the trigger is required for it to reset. I guess what was said during the phone call was that perhaps it is the case that that adjustment is too tight, and the trigger is reset basically during the recoil.
Another thing that we speculated about was that it was related to screw #4, i.e. what you said above about the two release levers. There is a bit of noticeable creep (when one pays attention) but not too much.
The third thing you mentioned is interesting: .32 S&W long WC is not trivial to come by, and I managed to pick up a single box (50) of Fiocchi, and then I have managed to get ahold of a bunch of Sellier & Bellot. I also have a few Lapua (the 83-grain ones, I think). I have not tested the Lapua yet, I do not think I got a single double-fire with the Fiocchi (and I have no more of them at the moment). This theory does make sense: the slide comes back, the hammer comes after and the firing pin strikes the cap as the cartridge comes to a stop: boom. I will investigate, but it will take a bit of time!
The manual lists these springs as "4014 bolt spring" (for the MG2(E) as 2014), but there is but a single variant of it. Is that some kind of special order? I can contact MatchGuns directly; I have ordered directly from Italy before.
Re: MG4 double fire
It sounds like you may be able to fix it with the right ammo. If you can find some...
The MG2 manual also only list the recoil springs with the one part number (2014). There is no indication in the manual I have that there are different strengths avaiIable.
I would contact the factory and ask them what ammo they recommend and if different springs are available.
The MG2 manual also only list the recoil springs with the one part number (2014). There is no indication in the manual I have that there are different strengths avaiIable.
I would contact the factory and ask them what ammo they recommend and if different springs are available.
Re: MG4 double fire
If you want to try different recoil springs (and they are available), it helps if you can figure out what you've got. You need the length (which is easy), the outside diameter (easy), the number of turns and the wire diameter. The number of turns can be a little tricky. I made up a template to make it easier to count accurately (attached). It's designed for Benelli MP90/95 springs and MG2 springs, so I don't know how well it will work for the MG4, but it may help.
Measuring the wire diameter is also tricky, because a very small change in the wire diameter has a big effect on the strength. A simple caliper isn't really accurate enough to provide the required precision. The best way to do it is to use a micrometer. Find a drill bit whose shank is a snug fit inside the spring, and then use the micrometer to measure the diameter of the drill bit and then the outside diameter of the spring with the drill inside. The wire diameter is half the difference between those two measurements.
Here's a table of the MG2 springs I've encountered:
I ordered (in theory) a set of all three possible strengths to experiment with. If you look closely, the "Soft" and "Normal" springs I received are basically identical... Based on the wire diameter, it looks like all three of the pistols came with "Soft" springs and they sent me two sets of "Normal" springs.
If you can tell the factory what the measurements are of the springs you have, they should be able to tell you what strength they are. If you are experiencing doubling, you want springs that are softer. If they don't have multiple spring strengths, or you already have the softest ones, you could buy a pair of the same strength and cut turns off to weaken them. If you are getting doubling with only 1 round in 10, it shouldn't take too much trimming to fix it. You may want to keep two sets of springs handy to deal with whatever ammo you can get at a given time.
Measuring the wire diameter is also tricky, because a very small change in the wire diameter has a big effect on the strength. A simple caliper isn't really accurate enough to provide the required precision. The best way to do it is to use a micrometer. Find a drill bit whose shank is a snug fit inside the spring, and then use the micrometer to measure the diameter of the drill bit and then the outside diameter of the spring with the drill inside. The wire diameter is half the difference between those two measurements.
Here's a table of the MG2 springs I've encountered:
If you can tell the factory what the measurements are of the springs you have, they should be able to tell you what strength they are. If you are experiencing doubling, you want springs that are softer. If they don't have multiple spring strengths, or you already have the softest ones, you could buy a pair of the same strength and cut turns off to weaken them. If you are getting doubling with only 1 round in 10, it shouldn't take too much trimming to fix it. You may want to keep two sets of springs handy to deal with whatever ammo you can get at a given time.
Re: MG4 double fire
I have sent an email to MG; will see if they reply. It does not look like anyone is monitoring their email and I was not able to parse the Italian message on the answering machine.
Re: MG4 double fire
My understanding is that they are undergoing some high level ownership reorganization. It is likely that support staffing may be sporadic until the dust settles.
Re: MG4 double fire
Yes, something is going on for sure! There is ostensibly a letter on the way from MG to me with a narrower front sight. I have sent the money but never received a confirmation, so it may or may not be on the way. If it does not arrive this week it probably is not!
I was planning on buying a set of spare parts so that I have them on hand if anything happens, an exercise in guessing how probable it is that I need them and weighing that against the cost of having them on the shelf uselessly. I was thinking of getting a couple of spare 4014 (bolt spring) anyway, together with a few other parts that I GUESS may need replacing within a few years, like 4013 (firing pin), 4034 (screw for trigger etc) and (4063) hammer spring. If I do find a source of spare parts, are there, in your experience, any other parts I should go for given the current situation?
I was planning on buying a set of spare parts so that I have them on hand if anything happens, an exercise in guessing how probable it is that I need them and weighing that against the cost of having them on the shelf uselessly. I was thinking of getting a couple of spare 4014 (bolt spring) anyway, together with a few other parts that I GUESS may need replacing within a few years, like 4013 (firing pin), 4034 (screw for trigger etc) and (4063) hammer spring. If I do find a source of spare parts, are there, in your experience, any other parts I should go for given the current situation?
Re: MG4 double fire
I've had to replace quite a few parts over the years, either because they wore prematurely, or broke. They've made a lot of design changes in the MG2 to address those issues, but only time will tell how successful they were.
I have had to replace the following parts due to wear or breakage:
Bullet insert lever (broke) (design has been changed, so far so good)
Hammer spring (broke after ~ 15K rounds) ( I think this was due to a manufacturing flaw, but it's hard to tell how common that is)
Extractor (broke) (bad geometry, new geometry should be better)
Extractor spring (wear)
Primary & secondary release levers (excess wear)
I had to replace the hammer as well, because they new release levers wouldn't work with the old hammer. The hammer has to be carefully fitted to work with the secondary lever.
I've always bought a replacement firing pin for almost every target every pistol I've owned, just in case. The firing pin in the MG2 is so short and fat that I can't ever imagine one breaking. The MG4 may be a little more delicate.
I have had to replace the following parts due to wear or breakage:
Bullet insert lever (broke) (design has been changed, so far so good)
Hammer spring (broke after ~ 15K rounds) ( I think this was due to a manufacturing flaw, but it's hard to tell how common that is)
Extractor (broke) (bad geometry, new geometry should be better)
Extractor spring (wear)
Primary & secondary release levers (excess wear)
I had to replace the hammer as well, because they new release levers wouldn't work with the old hammer. The hammer has to be carefully fitted to work with the secondary lever.
I've always bought a replacement firing pin for almost every target every pistol I've owned, just in case. The firing pin in the MG2 is so short and fat that I can't ever imagine one breaking. The MG4 may be a little more delicate.
Re: MG4 double fire
Thanks, that is very useful to know! The firing pin in the MG2 does look very robust. I do have a replacement for it, but I have not gotten that far with the MG4 yet; it is just a couple of weeks old for me.
Re: MG4 double fire
Well i had a mg2 firing pin break on mine. Had it replaced with one i had ordered when i received it. It was slightly different. It had a chamfer on the rear top than a square cut. i wonder if i may have to order some spare parts
Re: MG4 double fire
Sounds like you had an early pistol. All the firing pins I've seen have the bevel.
Out of curiosity, where did it break? The weakest points would be the cut in the middle for the retaining pin, and the thin section at the front that strikes the rim.
Out of curiosity, where did it break? The weakest points would be the cut in the middle for the retaining pin, and the thin section at the front that strikes the rim.
Re: MG4 double fire
in the middle where the retaining pin cut is located.
Re: MG4 double fire
Interesting. Sounds like they cut the slot too deep. If you dry fire a lot, the back end of the notch is what prevents the firing pin from going too far forward. That shouldn't be an issue in a centerfire pistol, but it's important in the .22's to prevent damage to the breech face.
Re: MG4 double fire
Interesting, indeed.
Both my MG2 and MG4 have a dryfire capability with the safety on. The hammer only falls very little and is well away from the firing pin instead of going a full stoke to the firing pin.
Even so, my MG4 firing pin broke.
The MG4 firing pin is tapered. So is the AW93 which supposedly allows the pistol to be dryfired. The taper on the AW93 firing has a relatively long taper while the MG4 is very, very short. When I replaced the MG4 firing pin, I failed to check the inside of the firing pin chamber to see if it was also tapered or simply straight. If straight, that could tend to place more force on the end of the firing pin.
The design of the MG4 firing pin is somewhat similar to that of my Pardini SP where a small circular grove cut immediately behind the end was apparently the weak point of both because both broke.
I would tend to think that MatchGuns and Pardini are no different that other gun manufacturers in that they are at the mercy of subcontractors for many parts. The same kind of thing appears to have happened to Walther regarding ejectors on the GSP's.
Perhaps the quality of metallurgy is the real culprit.
Both my MG2 and MG4 have a dryfire capability with the safety on. The hammer only falls very little and is well away from the firing pin instead of going a full stoke to the firing pin.
Even so, my MG4 firing pin broke.
The MG4 firing pin is tapered. So is the AW93 which supposedly allows the pistol to be dryfired. The taper on the AW93 firing has a relatively long taper while the MG4 is very, very short. When I replaced the MG4 firing pin, I failed to check the inside of the firing pin chamber to see if it was also tapered or simply straight. If straight, that could tend to place more force on the end of the firing pin.
The design of the MG4 firing pin is somewhat similar to that of my Pardini SP where a small circular grove cut immediately behind the end was apparently the weak point of both because both broke.
I would tend to think that MatchGuns and Pardini are no different that other gun manufacturers in that they are at the mercy of subcontractors for many parts. The same kind of thing appears to have happened to Walther regarding ejectors on the GSP's.
Perhaps the quality of metallurgy is the real culprit.
Re: MG4 double fire
Gwhite wrote: ↑Mon Jun 10, 2024 12:55 pm If you want to try different recoil springs (and they are available), it helps if you can figure out what you've got. You need the length (which is easy), the outside diameter (easy), the number of turns and the wire diameter. The number of turns can be a little tricky. I made up a template to make it easier to count accurately (attached). It's designed for Benelli MP90/95 springs and MG2 springs, so I don't know how well it will work for the MG4, but it may help.
Recoil Spring Gauge.pdf
Measuring the wire diameter is also tricky, because a very small change in the wire diameter has a big effect on the strength. A simple caliper isn't really accurate enough to provide the required precision. The best way to do it is to use a micrometer. Find a drill bit whose shank is a snug fit inside the spring, and then use the micrometer to measure the diameter of the drill bit and then the outside diameter of the spring with the drill inside. The wire diameter is half the difference between those two measurements.
Here's a table of the MG2 springs I've encountered:
MG2 Recoil Spring Table.jpg
I ordered (in theory) a set of all three possible strengths to experiment with. If you look closely, the "Soft" and "Normal" springs I received are basically identical... Based on the wire diameter, it looks like all three of the pistols came with "Soft" springs and they sent me two sets of "Normal" springs.
If you can tell the factory what the measurements are of the springs you have, they should be able to tell you what strength they are. If you are experiencing doubling, you want springs that are softer. If they don't have multiple spring strengths, or you already have the softest ones, you could buy a pair of the same strength and cut turns off to weaken them. If you are getting doubling with only 1 round in 10, it shouldn't take too much trimming to fix it. You may want to keep two sets of springs handy to deal with whatever ammo you can get at a given time.
Tried an internet search for the spring parameters listed and can't find anything. I am probably entering incorrect info. Can you provide the source for the springs listed please (S/N 1087, 1088, and 1225)?
Thanks
Re: MG4 double fire
Those are the serial numbers of the three pistols the various springs were found in, NOT the part number for the springs. MatchGun doesn't provide any clear indication of the difference between the springs, so my only choice was to measure them carefully. That was how I found out that two of the pairs of springs they sent me were the same strength, not different as I had requested.
Re: MG4 double fire
We recently came across a new MG4 ACP with double fire issue. The ammo we used was custom loaded. Jon did a thorough adjustment on all the trigger setting screws. The pistol still fired two shots consecutively sometimes.
After Jon took a careful look inside the pistol frame, he saw the front bottom side of the release lever (pn 2044) was touching the upper rear end of trigger holder or trigger bar (pn 2031, portagrilletto) when the trigger was pulled all the way to the back. Please see the attached drawing cropped from the user manual.
Jon used a Dremel grinder to remove a small amount metal from the front bottom surface of the release lever. The upper arrow in the attached drawing points to this surface. This solved the double fire issue.
Good luck in fixing the double fire issue.
After Jon took a careful look inside the pistol frame, he saw the front bottom side of the release lever (pn 2044) was touching the upper rear end of trigger holder or trigger bar (pn 2031, portagrilletto) when the trigger was pulled all the way to the back. Please see the attached drawing cropped from the user manual.
Jon used a Dremel grinder to remove a small amount metal from the front bottom surface of the release lever. The upper arrow in the attached drawing points to this surface. This solved the double fire issue.
Good luck in fixing the double fire issue.
- Attachments
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Re: MG4 double fire
Thanks for the suggestion! I have not shot it much for a while now, because the extractor broke a month ago. However, it seems like I am getting double shots primarily with some brands of cartridges. If I find some that work reliably and seem accurate enough then I may refrain from doing modifications. I will try to remember to report back once I have a bit more data, but it may take a while!