Need Help to Diagnose problem with my Match Guns MGH1

[Heavypellet]

Hi,
I have a MGH1 air pistol, after 2 years, the gun's muzzle velocity went from 490 fps to 120 fps. I tried contacting Match Guns many times and after 3 weeks, they final replied. They told me to adjust the air pressure regulator screw, which I did. I was able to get the gun's muzzle velocity up to 400 fps and any other adjustment only brings the velocity.

Does anyone know what is wrong with my MGH1?

[william]

To the tune of Mrs. Robinson:
Where have you gone, Don Nygord?
Our nation turns its lonely eyes to you.
Woo woo woo.

Sorry, I couldn't stop myself.

[Shiloh]

I had a MG-1 which had an adjustment screw in the upper area of the rear of the pistol to regulate velocity. It was much bigger than other adjustment screws.

The manual stated that any adjustment should be done very carefully or the pistol could be ruined. If you have the manual that came with the pistol, then I would imagine that a similar warning appears as well. I recall the adjustment being very fine and exact so a very small amount of turn (clockwise to increase velocity) should attempted with regular and constant velocity checks.

I have since moved on to a Steyr EVO.

Northern Italy has been essentially locked down for a while because of the carona-virus. Hopefully, Stephano at MatchGuns is well. His English is superb and I always found him most helpful with info and parts for my MG-1 and MG-2.

You should be try to be patient and wait until the crisis in Northern, and now the rest of, Italy recovers. Hopefully, that will be in the near future.

Finally, and hopefully, the author of the previous answer to your post did not post the other 990 as being as inane and useless. He should have the decency to remove his most recent on this topic.

[Rover]

Oh, William is OK for a Democrat. He just can't carry a tune.

[Heavypellet]

Shiloh,
Thanks for trying to help. Stefano did reply to me and he said “You should make a test: please turn CW the wheel with holes of the pressure regulator for about 10-15 minutes and check again the speed to verify if it changing … You only have to turn CW for 10-15 minutes (less than 90°) the wheel indicated in the picture. In this way you will increase the working pressure of the pistol.”

I assumed that is the screw that controls the regulator’s pressure. That screw is in front of the trigger unit. The velocity increases as I keep turning and decrease back down as I continue turning, I was only able to get the velocity up to 400 fps max and not 490 fps.

[Rover]

The first (and cheapest) thing I would try is a new striker spring. Just go to the hardware store and see if you can find something like it before doing anything else.

[Heavypellet]

But if the Striker spring is broken, I shouldn't be able to vary the muzzle velocity from 120 fps to 400 fps, right?
I think most likely is a bad pressure regulator follow by maybe the Valve.

[bigaaron]

The first (and cheapest) thing I would try is a new striker spring. Just go to the hardware store and see if you can find something like it before doing anything else.

I agree, I have an lP10E that had a broken striker spring. Every couple of months the velocity would drop off some.
I would adjust the screw and was able to get the velocity back. This happened a couple of times over a year or so.
I ended up turning the screw in so far until it started blocking the absorber. I removed the spring and it was broken.
Replaced the spring, problem solved. Before I got a new spring from Pilkgun, I found a spring close to the size and length as the old one and it worked great.

Aaron

[Heavypellet]

Arron,

Today I took out my MGH1 Hammer and Hammer spring, spring is not broken, both parts looks brand new. I think most likely is the Regulator follow by the Valve (which I doubt).

It amazes me how small the Hammer and Hammer spring are compare to the ones in my 10-meter air rifle.

[David M]

You should make a test: please turn CW the wheel with holes of the pressure regulator for about 10-15 minutes and check again the speed to verify if it changing … You only have to turn CW for 10-15 minutes (less than 90°) the wheel indicated in the picture. In this way you will increase the working pressure of the pistol

If possible can you please post the full reply including the picture.

[Heavypellet]

Match Guns stop replying to me a few days ago saying their company (in Italy) shuts down for 2 weeks due to the CoronaVirus and that I should contact them again on April 6.

[django]

Hammer spring look good but some it can make velocity drop. Turn spring tension screw right clock turn or adding small ring or small ballbearing can increase tension add more velocity. Take look or replace your spring b4 mess with regulator

[Heavypellet]

I took out the hammer spring and spring guide also came out. They both look brand new. I reinstalled them and put tension screw back in, no change, adjusted the screw, very little change, much more change when I adjusted the air pressure regulator screw. Still waiting for Match Guns in Italy to reply. They said they are still in Virus shutdown mode until maybe April 9, maybe.

[Heavypellet]

See attached picture.

[trev]

I have an MGH1 and I have found the velocity changing on it own. I set the velocity to 535 fps and it was very consistent over 15 shots it varied just 2 fps but two weeks later it sounded soft when I shot it. After checking the speed again, I found it was recording 467 fps when adjusting the part to increase the velocity it moved very easy with no resistance. When adjusting an LP10 there is a small grub screw that locks the adjusting screw but on the MGH1 there is no such screw they just hope the spring compression keeps it stable. I think Match Guns should think about a locking screw on the velocity adjusting screw.
Having seen the picture on the previous post I am now going to remove the adjusting screw and check the spring.

[Rover]

A small dab of nail polish will keep the screw from backing out.

Try the "Precious Pink" you use on your toe nails.

[Heavypellet]

what about loctite blue?

[rmca]

what about loctite blue?

Also works, but it's not as flashy as the "Precious Pink"!! ;)

Anything that will prevent the screw from coming undone is fine... Locktite (non permanent), nail varnish, even a very small dab of superglue.

Hope this helps

[Gwhite]

When using commercial threadlockers like LocTite, I always start with the weakest I can and work my way up. LocTite purple (#222) is designed for screws that may require adjustment, and works fine in a lot of places where the manufacturer didn't feel any threadlocker was needed. If that comes loose, I go to LocTite blue (#242). I hardly ever use the red stuff (#262), but that's often all most hardware stores carry. It's pretty much permanent on the small screws found on target pistols.

Another option is VibraTite VC-3, which instead of being a liquid that hardens after you assemble things, it's applied to the screws beforehand. It's basically a medium-soft plastic dissolved so you can apply it to coat the threads. You then let it harden and it acts like a quick version of a "Nylock" bolt that has a small piece of nylon stuck in the threads. You can even pre-treat screws with it and keep them in storage indefinitely. I first ran across it packed with some new rifle scope mounts, and it's often the first thing I try now. It's sort of an industrial version of nail polish.

My wife & I have a pair of MG-2 pistols, and the screws that hold the front muzzle weights keep coming loose. I tried VC-3, and that didn't do it, so I'm about to clean everything carefully and try LocTite blue.

That brings up another issue, which is cleaning any oil off both the inside & outside threads before you apply any threadlocker. The screws are usually easy, but getting the oil out of small internal threads can often be difficult.

[Heavypellet]

I have an MGH1 and I have found the velocity changing on it own. I set the velocity to 535 fps and it was very consistent over 15 shots it varied just 2 fps but two weeks later it sounded soft when I shot it.

I do notice that the MGH1 pistol doesn't spit out a lot of air like other air pistols. Even my HW75 spits out more air, with that said I notice there is a wide spread of muzzle velocity from a small pellet weight difference. I also think that the factory adjust the pistol to put out Max velocity or close to it. So if the parts starts to break-in over time, that velocity may shift a lot.