Finnish M39 extraction issues

[Lp1911]

Hi everyone,
So I have been fiddling with the extractor and the feeding on this rifle has become much smoother than when I first got it. Today at the range, the first 20 rounds were feeding and extracting like butter. Then I started having the casing come out fine, but seemed to catch on the next round’s rim and I had to pull it out by hand. This was all with various steel cases. Then I switched to some PPU brass cased ammo and again the cases started flying out when pulling the bolt back. Switched back to steel and the problems came back. Then I let it sit for a while to when it was just warm to the touch and steel cases were extracting better. Mind you, this is not any problem with a sticky bolt or anything like that, it is all about pulling the bolt all the way back and getting something of a jam between the pulled out casing and the next round. When I tested at home, I only had brass snap caps to play with and I saw none of these issues, nor with steel cases on the first 20, or so, rounds. Any ideas on how to fix this (using brass only ammo is not a solution I want )?
Appreciate any help.

[ffuries]

Are these lacquered cases? The reason I ask, is it seems to an issue with some people. I've heard it's due to the lacquer getting warm and becoming sticky.

I haven't had any issues, so I can't speak to whether that's a real thing or an internet story, but something to think about.

[Lp1911]

The second 20 rounds were in fact lacquered, while the first 20 were polymer coated, but then afterwards I tried the polymer coated ones and still had issues.
When I got home, I took out the barreled receiver and noticed some Cosmoline gunk around the ejector/interruptor, so I took out the ejector cleaned it, cleaned the slot where it goes and then put some moly grease on the piece. My theory is that the interruptor was somehow not working quite right, causing the next round to go up too high. I can’t say this cleaning will be a fix, since if Cosmoline would melt it would actually be a lubricant, but who knows...

[SA1911a1]

The second 20 rounds were in fact lacquered, while the first 20 were polymer coated, but then afterwards I tried the polymer coated ones and still had issues.
When I got home, I took out the barreled receiver and noticed some Cosmoline gunk around the ejector/interruptor, so I took out the ejector cleaned it, cleaned the slot where it goes and then put some moly grease on the piece. My theory is that the interruptor was somehow not working quite right, causing the next round to go up too high. I can’t say this cleaning will be a fix, since if Cosmoline would melt it would actually be a lubricant, but who knows...

That stuff is not Cosmoline. It is ear wax. It was harvested from the soldiers weekly, boiled down to remove the impurities, and then repackaged as gun preservation grease. It is not a very good lubricant, especially when it is 50 years old. Harvesting the ear wax from the troops saved resources and made sure that the soldier's hearing was among the best in the world.

You did well if you got the extractor out and cleaned and oiled it. You also need to make sure that none of the earwax is hardened in the chamber. Most Mosin-Nagant problems are from a dirty chamber.

[Lp1911]

No ear wax or any other wax in the chamber. The rifle was initially full of Cosmoline, yet the guy who sold it claimed to have fired it and found it accurate. I suppose it’s possible, yet he must never had taken the receiver out, which though not inside the receiver but pretty much everywhere else was absolutely covered in Cosmoline, or ear wax, some inside the bolt as well; took some serious cleaning...
Anyway, the interruptor does not protrude as much as in my other M39, though it does interrupt when dry cycling, and of course with dry cycling, I can move the bolt pretty smoothly and gently through the whole cycle with snap caps and they end up in a neat little pile a couple of feet away. So will have to see next time out if I can reproduce the problem after all the cleaning around the ejector/interruptor.

[steelbuttplate]

No ear wax or any other wax in the chamber. The rifle was initially full of Cosmoline, yet the guy who sold it claimed to have fired it and found it accurate. I suppose it’s possible, yet he must never had taken the receiver out, which though not inside the receiver but pretty much everywhere else was absolutely covered in Cosmoline, or ear wax, some inside the bolt as well; took some serious cleaning...
Anyway, the interruptor does not protrude as much as in my other M39, though it does interrupt when dry cycling, and of course with dry cycling, I can move the bolt pretty smoothly and gently through the whole cycle with snap caps and they end up in a neat little pile a couple of feet away. So will have to see next time out if I can reproduce the problem after all the cleaning around the ejector/interruptor.

The spring tension on the interrupter is what can screw things up. Check it against another rifle that works right.