Need Help to Diagnose problem with my Match Guns MGH1

[Heavypellet]

I increased the Hammer Spring tension. The pistol shoots at 495 fps with 7.0 grain pellet. I check the velocity again the next day and the muzzle velocity dropped down to around 250 fps. What happened?

[northpaw]

What happened?

You´ve got a lemon.

[fc60]

Greetings,

Springs are fairly durable. The fail over a long period of time.

I would be checking out the neoprene seals.

Might be a worn seal that holds air today and not tomorrow.

Cheers,

Dave

[rmca]

Greetings,

Springs are fairly durable. The fail over a long period of time.

I would be checking out the neoprene seals.

Might be a worn seal that holds air today and not tomorrow.

Cheers,

Dave

+1 on replace the seals.

If that doesn't fix it, get a new regulator.

Hope this helps.

[Heavypellet]

thanks rmca, I suspect the problem is most likely the Regulator.

[Heavypellet]

Update: Match Guns email me to say that they are shut down due to COV19 and that I can try to contact them on May 13, 2020.

[Heavypellet]

Still wanting for Match Guns tech support, hopefully they will re-open on May 13. In the mean time, I decided to take my Hammerli Master out and shoot again.

[Heavypellet]

Match Guns of Italy finally got back to me and offer to sell me a pressure regulator for 65 euro + 15 euro for shipping. They couldn't tell me if this will solve the problem I have. I don't know for sure if this will solve my MGH1 light air pistol's problem. Match Guns don't have any support in the USA.

I have decided to sell my MGH1 light pistol. If anybody is interested, please make an offer.

[Heavypellet]

Here is a picture of my MGH1 Light. As I was posting this picture I was thinking how funny it is that none of my very inexpensive "Made in China" airguns ever failed, but this expensive MGH1failed. I won't be laughing anymore at the "Made in China" airguns again.

[Pyroman]

I had a very similar problem with mine last year. The velocity started dropping then got to the point where the pellet wouldn't leave the barrel. Played with the regulator a bit and it would be fine for a day or so then back to not working. Bought a new regulator from Stephano, changed it out and now I've been fine for a year. I don't understand what was wrong though. There regulator looks like a stack of weird washers. But if they don't sit JUST right, it all goes to heck. Someday I'd like to spend a week at Matchguns and learn to be an expert with servicing them.

[Heavypellet]

Hi Pyroman,

Thank you for your comments. Those washers when stacked in series become a spring. They are called Belleville spring washers. I have a HW100 air rifle with those washers in the regulator and it never failed, I have the gun since 2004. My FWB P70 rifle regulator has not failed me yet and I have it since 1999. Since we have the same problem, I think Match Guns' regulator is designed poorly and that is why I don't want to buy a replacement regulator from them. I am now shooting my Hammerli Master and the gun itself is more accurate than my MGH1 when it was working, BUT my Hammerli Master doesn't have the grip with a palm shelf, thus harder to shoot accurately.

My Match Guns MGH1 Light air pistol is for SALE.

[spektr]

Its too bad you are giving up on it..... The nature of Belleville washers is to stick together and not function when improperly maintained.... Our guns are usually fed a very dry compressed air that does absolutely nothing to keep a Belleville stack happy...... The fix to a stack that is not moving as it should, is to dissassemble them, clean off the old lubricant that is now a varnish sticking them together a d reassemble them...... They require a small drop of a silicone based oil at the end of eaxh shooting season to prevent the problem moving forward..... The suggestion to increase the air screw adjustment would work if the washers were moving as they should..... half the time, the washers will become mobile with application of oil into the gun with the tank off and 25 rounds or so to get the oil thru the gun..... Now dont flood it, because a dab of oil gos a long way. Maybe 1 good drop.......

[Heavypellet]

When you said “Our guns are usually fed a very dry compressed air that…” You sounded like you worked for Match Guns. Do you?

Thanks for the reply and suggestion; you are more helpful than the support I gotten from Match Guns. I already took those factory Belleville washers out and they are dry and not sticky, see picture. I measured those Washers with my Caliper and tried to see if McMaster-Carr has something close in dimension and they DON’T. I could buy a new Regulator offered to me by Match Guns for 65 Euro + 15 Euro for shipping. I don’t know if Match Guns will send me an entire Regulator for 80 Euro or just 7 Belleville washers.

Also around my MGH1’s loading port sometimes the air leak. I only had the gun for 2 years + 1 month before all these problems showed up, I didn’t shoot the pistol much cause I am a rifle shooter.

[rmca]

The way the washers are stacked is also important.
From the pictures I think you can see the rub marks on them. They are not strait, more like a (
Steyr's washers are stacked like this ( ) ( ) ( ) ( ) and are 8 total. Macthgun's should be similar...

Hope this helps

[Heavypellet]

I counted only 7 washers. They were stack like this ()()()(

[rmca]

I figured that much by the picture.
The way they are stacked seams correct, even if they are "only" seven.
Seams odd but without an exploded view or the pistol's parts I can't say if there is one missing.
I would check if any of them is like this | instead of (

I not seeing a way to solve it without ordering a new one. They are usually a single unit for the manufactuers and are not intended to be taken apart. I assume that Matchguns would send you a complete unit.

Hope this helps

[spektr]

No I don't work there, BUT the pictures are showing exactly what I was speaking of. Belleville washers slide against each other when being compressed. In your 2 left hand pair of washers, the contact surface is bright and shiny where they rub against each other.... Contrast that with the right hand pair of washers where there is obvious corrosion or congealed lube on the sliding contact face.... This means the washers will not compress and decompress predictably..... Again, they need to be degreased, polished and lightly lubed before you reassemble them...... I would go so far as to lightly burnish all of them ON THEIR CONTACT SURFACES ONLY with some 2000 grit paper doing so wet... To me it looks easily fixable with a few minutes of polishing.....

[rmca]

I would try spektr idea, but I woun't hold my breath on it working.
Those washers are rather stiff, and since your's is not working, I would assume that one or more has lost it's springness.
You wont make anything worse if you clean, degrease, check for burrs, and then lightly lube them.

Hope this helps

[Heavypellet]

rmca,

Thank you for your suggestion. Like I said before, I cannot find any washers with those dimension or close to it. I even tried places like McMaster-Carr.

My MGH1 Pistol is still up for SALE, please make offer.

[rmca]

From my experience, selling a pistol with a malfunction will hit you harder financially than reparing and selling it.
You you don't want the trouble of fixing it, be prepared to take a heavy hit on the price.
And they also take longer to sell if you don't price it accordingly.

Good luck with it.