Matrix (S&T/AGM) MG42 - In-depth Look / Upgrade Blog

[KenTsui]

Originally Posted by Nailcake

Hello,

I just registered to say a few things;
First I should thank you for this thread, it is the only review I could find on this MG(I own this one myself obviously). I had to change the spring, but since the center guide is stuck in the upper part of the gearbox I had to open it. I got stuck at one point and was only able to continue when I found this thread and learnt about the little spring which you mentioned in the pistolgrip.

Secondly, the one I have is the AGM MG42, which is actually the same gun from the same factory as the S&T/Matrix MG42, just with a different brand on the box. I actually wanted to buy the gun from Evike, but then they decided not to ship abroad.
Unaltered the gun shoots 420fps, too much for fields around here(Belgium).

Also, be careful with the externals, they are rather fragile. The feedingtray on mine arrived with damaged hooks and had to be replaced(now an expensive hardened steel feeding tray with a ten year warantee on it). The aluminium in which the gun is made is flimsy and bends quickly.
I havent been able to take it to a game myself but have already heard from other users about a number of smaller problems with this gun, like batteries in the drummag loosening and the mag no longer feeding when firing on the move because of it.

I hope you dont mind digging here for this purpose.

Thanks for adding extra information. I'll add this quote to the bottom of my review for others to see if you don't mind. I will also update my title as I remember the AGM thing in the WW2 thread, according to a trusted source.

I also had a problem with the feeding tray hooks. They were too far apart and did not allow a solid mounting of the drum. I took a risk and bent them closer together. Thankfully, it did not break off, but you are right, all the metal parts feel weak.

[Gcold]

Thanks for the review. As a WW2 weapon fan, this mg42 looks pretty nice to me.

[beastor]

Thanks for this blog, I am having real issues trying to remove the spring, the thing just seems jammed but I will try and use some of the tips to get it out.

The hop also seems to have no effect what so ever so I was hoping to try and access it. I assume you have to remove the gear box so you have to get to it by removing the trigger and grip as well as the side screws on the reciever?

Thanks again!

[KenTsui]

Originally Posted by beastor

Thanks for this blog, I am having real issues trying to remove the spring, the thing just seems jammed but I will try and use some of the tips to get it out.

The hop also seems to have no effect what so ever so I was hoping to try and access it. I assume you have to remove the gear box so you have to get to it by removing the trigger and grip as well as the side screws on the reciever?

Thanks again!

Yea, it seems like everyone is having problems with the QD spring. Just do your best to spin the sector gear so that it's not engaging the piston and release the ARL so there's as little spring/piston/sector interaction as possible.

To remove the gearbox, yes, you have to lower and the screws on the side of the upper. If you don't split them apart, you can't take them out of the receiver.

To access the hop-up chamber, technically, you don't have to remove the gearbox. That's provided you are comfortable with taking the barrel retaining "C" clip off while it's still in the receiver. After that, just slide the inner barrel forward and there'll be only one screw that holds the chamber to the gearbox.

It's probably easier to just take out the gearbox though. You'll have to eventually fix the QD spring anyway if you ever plan on having this feature. Also, it will make taking out the gearbox a lot easier in the future.

[beastor]

Thanks for the quick reply, I have to admit though I still cant get the gearbox out! I managed to get the grip to slide a little back and forth but the whole thing is still jammed!:banghead:

Any chance you could post a pick highlighting which actual screws to take out and in what order? A lot to ask I know but this is really stumping me.

Regards

[KenTsui]

Originally Posted by beastor

Thanks for the quick reply, I have to admit though I still cant get the gearbox out! I managed to get the grip to slide a little back and forth but the whole thing is still jammed!:banghead:

Any chance you could post a pick highlighting which actual screws to take out and in what order? A lot to ask I know but this is really stumping me.

Regards

Okay, I will try and do something like that when I have time tomorrow.

[beastor]

Cheers mate, I would love to get this sorted out for this Sunday...

[KenTsui]

As promised, this might help those of you having trouble with removing the gearbox. It's my first instructional video, so go easy on me.

http://youtu.be/SyTptjSsyRo

[beastor]

KenTsui, I thank you!

Spring changed to a more face friendly 330fps and hop unit fixed!

Thanks again, that youtube movie was invaluable!

[duggan69]

Having problems with your mg42 gear box and drum mag. Don't have the inclination to fix it yourself. having fielded this in orig configuration and having it fail miserably....I decided to fix that once and for all. I can help you too.

Let me rework and rewire it for you. When the gear box is repaired you will get better performance from the drum mag with out the constant feeding problems. you will no longer need to use the drum battery pack.

All you need do is send me the gearbox and top and bottom. I will fix, then send back. I can do any upgrades to it. if you want you can send the drum mag also. All my work is double tested.

email panzerjj@hotmail.com or shoot me text here

[Rawbbeh]

Hey kenTsui!

Wanted to follow up,with you on my AGM (S&T which is the hub that distributes for AGM) MG42.

Worked with a pretty skilled tech who used to work for G&G who happens to be super OCD about making guns work perfectly. Anyways, I left it with him and here's the initial tweaks and upgrades he did.

Shimmed the gears - he says the gears are pretty solid for being Chinese...recommends running them until they give out

Shimmed the hop up slider so that it doesn't jerk around when trying to slide it..it glides much better and will hold the setting without vibrations moving it

Replaced piston and cylinder head, these he said weren't great and already showing wear even after 5k rounds cycling through it.

Greasing the gearbox (always a good thing)

Soldering the wires to the motor

Installing a mosfet on the trigger.

And for me, most importantly is rewiring the trigger so every time the gearbox fires, the box mag motor winds. Which, as the tech was telling me, was pretty stupid how they wired the trigger. The trigger contacts are copper, but the box mag is actually a pressure button that the trigger when pulled (with good force) pushes the button to make contact to wind the magazine. He says this was completely pointless, costs more money to manufacture, and isn't as effective as just wiring it with the trigger contact!

So anyways, needless to say, he wired the trigger to make it how it SHOULD have been (but better cause he's OCD and gave it much Love and Care)

I get the gun back Saturday and going to a game on Sunday. Can't wait to see how she does!!

[KenTsui]

Originally Posted by Rawbbeh

Hey kenTsui!

Wanted to follow up,with you on my AGM (S&T which is the hub that distributes for AGM) MG42.

Worked with a pretty skilled tech who used to work for G&G who happens to be super OCD about making guns work perfectly. Anyways, I left it with him and here's the initial tweaks and upgrades he did.

Shimmed the gears - he says the gears are pretty solid for being Chinese...recommends running them until they give out

Shimmed the hop up slider so that it doesn't jerk around when trying to slide it..it glides much better and will hold the setting without vibrations moving it

Replaced piston and cylinder head, these he said weren't great and already showing wear even after 5k rounds cycling through it.

Greasing the gearbox (always a good thing)

Soldering the wires to the motor

Installing a mosfet on the trigger.

And for me, most importantly is rewiring the trigger so every time the gearbox fires, the box mag motor winds. Which, as the tech was telling me, was pretty stupid how they wired the trigger. The trigger contacts are copper, but the box mag is actually a pressure button that the trigger when pulled (with good force) pushes the button to make contact to wind the magazine. He says this was completely pointless, costs more money to manufacture, and isn't as effective as just wiring it with the trigger contact!

So anyways, needless to say, he wired the trigger to make it how it SHOULD have been (but better cause he's OCD and gave it much Love and Care)

I get the gun back Saturday and going to a game on Sunday. Can't wait to see how she does!!

Thanks for your input, I've pretty much done everything you listed. It's good to have reassurance from a good tech.

Although, I'm not quite sure what he meant by shimming the slider on the hop-up. I tightened the screw on mine so it won't lose its setting but loose enough so that it can still be adjusted.

[Rawbbeh]

Originally Posted by KenTsui

Thanks for your input, I've pretty much done everything you listed. It's good to have reassurance from a good tech.

Although, I'm not quite sure what he meant by shimming the slider on the hop-up. I tightened the screw on mine so it won't lose its setting but loose enough so that it can still be adjusted.

He said he put a shim between the hop up and the screw or something. Basically, he disliked how when you tried to move the hop up it would jerk from spot to spot, so he gave it a little buffer to make it glide better and be less likely to lose its setting from vibrations and such in the gun

[Rafter_Man]

Hi KenTsui, your upgrade blog is excelent, thank you so much.

You should know that the 650mm barrel is definitly to long for the cylinder in this gun. Even a bore up kit probably won't be enough. I upgraded mine to a 6.03mm 509mm Madbull V2 barrel. Also, after chronoing mine i noticed that the FPS values didn't seem to match what the spring should deliver. The reason for that isn't an airseal issue though, but due to less compression on the spring. The R&D department who thought up that Gearbox left about 1cm more space between the cylinder and the base of the springguide, resulting in less compression and so less energy output.

Also I tried various nozzle/bucking combos to achieve a good and constant airseal. I installed two aftermarket airseal nozzles, the one you used(i also added an O-ring), which gave me horrible FPS differences (maybe do to the HU/GB missalignment) and a czech made one which worked better but was still off. But both nozzles don't have that tapped design the orginal MG42 nozzle has. I achieved the best results with the original bucking/nozzel combo after i added an O-ring to the nozzle. And I also removed the screw between the hopUp chamber and the gearbox because in my gun somehow, it was the reason for the mentioned misalignment between the HopUp and the GB. The spring pushing the HU to the gearbox is more than capable to hold the hopup in place.

[KenTsui]

Originally Posted by Rafter_Man

Hi KenTsui, your upgrade blog is excelent, thank you so much.

You should know that the 650mm barrel is definitly to long for the cylinder in this gun. Even a bore up kit probably won't be enough. I upgraded mine to a 6.03mm 509mm Madbull V2 barrel. Also, after chronoing mine i noticed that the FPS values didn't seem to match what the spring should deliver. The reason for that isn't an airseal issue though, but due to less compression on the spring. The R&D department who thought up that Gearbox left about 1cm more space between the cylinder and the base of the springguide, resulting in less compression and so less energy output.

Also I tried various nozzle/bucking combos to achieve a good and constant airseal. I installed two aftermarket airseal nozzles, the one you used(i also added an O-ring), which gave me horrible FPS differences (maybe do to the HU/GB missalignment) and a czech made one which worked better but was still off. But both nozzles don't have that tapped design the orginal MG42 nozzle has. I achieved the best results with the original bucking/nozzel combo after i added an O-ring to the nozzle. And I also removed the screw between the hopUp chamber and the gearbox because in my gun somehow, it was the reason for the mentioned misalignment between the HopUp and the GB. The spring pushing the HU to the gearbox is more than capable to hold the hopup in place.

Good points! It's funny you mentioned that, because this week I actually cut down the inner barrel.

I'm now using a 470 mm inner barrel, which, by my calculations, should give me a ratio of about 1.7.

I noticed the nozzle design difference when switching nozzles. So I measured the position of the bb with respect to the OEM one. I ended up using the Core PTS Masada nozzle. Some shaving of the tappet plate may be required to get that extra half a mm.

I hadn't noticed that about the spring compression length. Now I don't feel so bad that I'm not getting as much fps as I should. Thanks. If you don't mind, I'm going to add that to my first post.