Main topic: found some metal melted to my gas regulator which caused a couple jams

Here is the situation, went to the range (outside temp was prob around 90) took my E4 chambered in 7.62x39. I was shooting Fiocchi Brass, I was nto doing any rapid firing, I was going for accuracy so I was taking my time shooting, didnt overheat the barrel or anything. Anyways toward the end of my trip I had a few FTF's, I shot around 120 rounds total this trip, I got frustrated and left thinking maybe this fiocchi was really dirty ammo somehow and it got the regulator really dirty. I forgot to change my gas setting to high to test that part but I am glad i did not. I got home took the gas regulator apart and found some metal melted to my gas regulator and some more melted almost all the way around my gas piston rings. These appear to be copper in color so I assuming copper fouling? I have never seen copper fouling so I am asking yall what you think it might be. It chipped off really easy with a brass brush.

</a> IMG_9592 by vr4rhoads, on Flickr" />


IMG_9591 by vr4rhoads, on Flickr

Check the barrel gas port where they came out of.  It kind of looks like chrome plating came loose and the reason for the copper is that's what is used to coat the steel before plating with chrome.  You may have lost the chrome plate in the gas port.

So if I lost my chrome plating what does this mean for my rifle and gas chamber? I had to tap the whole assy out with a punch and hammer. It does look as if there are some missing on the inside...

then again I ran a soft piece of plaster throw the gas chamber and did not catch on anything as I ran it through on the sides.

Can you post a picture of the gas chamber?  If you did lose chrome, you need warranty work.  Start with MSAR and then call Ratworx.

The only thing you should see on the gas piston and valve is Black carbon.  Shiny metal is a bad sign by all accounts.

mk ill post a picture in five minutes

There is a line that goes allllll the way down the gas chamber, this part is whats left of the chrome lining it seems...... I have pics processing right now.

DSC_0001 by vr4rhoads, on Flickr" />


DSC_0005 by vr4rhoads, on Flickr

They are kind of hard to make out.... I can take better pictures if needed

Called Ratworx first, mainly because they are great to deal with, they said they have never had this issue yet and that I would have to go through MSAR sighhhhhh Hopefully they can rechrome the chamber or retool that machine to make me a new 7.62x39 barrel, wouldnt mind having a new barrel!

That is something I have not seen.  My guess is that this is residue from the ammunition.  There is no chrome lining in the gas chamber.

Glad you chimed in Dave, so copper fouling maybe? I will put my piston back in to see how the fitting is. Anyone else have any ideas?

I had what appeared to be copper residue "burnt" onto the inside of the gas piston tube (similar to what OP describes).  I used Mpro-7 copper terminator and a .40 cal brass brush to gently remove the copper colored spots.  My guess was that it was vaporized copper being deposited onto the inside of the gas piston tube during firing.  I should also note that the copper spotting on the inside of the gas piston tube lined up with the holes in the gas regulator.

ETA:
My experiance was with a Steyr Aug, not an MSAR.

After you used that did the issue ever come back? on the piston itself there were two spots that did not have melted material on it, what causes this by the way?

Chrome plating coming loose sounds extreme and would be one of the last things I would expect.

Sounds more ammo related than anything.

Any ammo even good quality name brand ammo can yield a bad batch on occasion...may have gotten some jacket fouling in the chamber.

I would clean it all up, re-assemble and try different ammo before I made any "needs repair" decisions.

You have some copper fouling on your Piston. Use Mpro-7 as suggested, it works great. I have seen copper fouling on the tails of M4 bolts, but then again, I shoot them for 10s of thousands of rounds Copper can get anywhere the gas goes to drive the weapon.

I guess their all different.  I shoot no less than 800 rounds per outing and haven't seen any copper or other metal flake in the gas chamber or piston.  

Clean it up and see what it looks like without the crud on it.  That shiny piece on the gas plug looks suspicious.

Ive already cleaned off the piston and plug, no damage or anything out of the ordinary.

I could have swore we were told they were chrome lined .