Mosin Nagant bolt won’t close

[14sutten]

Hello. I recently bought a m44 in very good condition. After buying some wolf ammo I went to the range and found it hard to close the bolt with a round chambered. I then looked up possible issues and took the rifle part and cleaned the barrel and chamber with boiling water/shotgun brass brush. I also cleaned the bolt and extractor as well. I switched over and tried some Yugoslav surplus but still has the same issue. The rifle will feed fine so rimlock isn’t an issue. The rifle will be able to push the cartridge into the chamber but not be able to close the bolt with the cartridge in there. I then open the bolt and remove the cartridge. After cycling the bolt the next round often goes in no issue however sometimes the bolt is hard to close. The bolt usually does not close on 1-2 out of the 5 but it varies. I am wondering what the next steps could be? I have not checked headspace so could that be an issue? Possibly the extractor is too far Bert towards the rim? The bolt also effortlessly opens so it is not a sticky bolt on opening.

[House Beagle]

Double check that the chamber is clean and clear of any grease or debris. If it’s not the chamber, I would suspect tight headspace. This can be verified with a set of headspace gauges.

[14sutten]

Alright I will get some headspace gauges. If the headspace is too tight what can I do to fix this? And would trying another Mosin bolt work? Also in the picture I have of the chamber is that little ring around the chamber an issue? I’ve cleaned the chamber but have not used the drill with the brush?

[millman]

If you could try a known good bolt in it, that would help you. You might rule out some issues.

[House Beagle]

Everything in the pictures you attached looked normal to me. If you find that the headspace is short, then you can change out the bolt head, and hope that the one you choose has more headspace than the previous one.

[14sutten]

Will do and thanks for the response from both of you!

[qz2026]

When you experience difficulty closing the bolt has the rim of the cartridge seated in the bolt face under the extractor? If not, then this could be your problem... As mentioned... It might be a good idea to test with another bolt or, at least, another bolt head. I'd pretty much doubt there is a headspace issue, at least with the rifle.

[kpangon]

It could be that your extractor is difficult to get over the rim of the cartridge when closing the bolt. To test if it's your extractor, take the bolt out of the gun. Place a round(it's best to use a snap cap, but if you don't have any be careful and follow basic firearms safety procedures) into the front of the bolt under the extractor, then carefully reinsert the bolt into the rifle being careful to not let the round fall off the bolt, the extractor should hold it in place. Then close the bolt, if it closes with no difficulty then you know your issue is the extractor overcoming the rim. If it is still difficult, then your problem is elsewhere.

[14sutten]

And if it’s easy then just order another extractor and swap it?

[kpangon]

And if it’s easy then just order another extractor and swap it?

I fixed my m38 myself. The angled part of the extractor that slides over the rim of the cartridge is where the issue is. I took a needle file and got a nice smooth angle on the extractor face. Then I polished it nice and smooth with 200 and 400 grit sandpaper. It's worked fine ever since.

If you decide to swap it out, getting a whole new bolt head will probably be easier. The extractors can be a real pain to get out sometimes.

[14sutten]

I’ll try and file that down. I’d that isn’t the issue will filing that down cause any damage in terms of making it hard to have the run slide over? And worst comes to worst a new extractor isn’t too pricey.

[willyj73]

There are a few things that could be going on:
1. Fouling, rust, ruptured case in the shoulder of the chamber or where the neck of the round enters the chamber.
2. Too long of a bolt head. As far as I know, Russia/Soviets did make longer bolt heads to address head space issues. I would think those would be marked.
3. Some type of obstruction in the bolt lug recess (rust, burr, or something)

A decent bore scope could help identify if the problem is in the chamber or bolt lug recesses. A bore scope is good to have, so it's not like you're wasting money on a one time use.
You could also try a different bolt or bolt head. If the bolt closes without issue, measure the bolt heads to see if bolt head length is the issue.
Could be the extractor claw as stated. Sometimes, filing the rough edges of the extractor claw can help alleviate issues. You don't have to file much--just a few strokes should smooth off jagged edges.

[RazorBurn]

I wouldn't be filing on anything myself. First thing to do is to check headspace. Once you do that then you'll know if you have a bolt head issue or not. Old Mosins are notorious for needing the bolt and chamber area cleaned thoroughly. In my experience the more rounds and hotter the barrel was, the worse it was. Inspecting and cleaning the chamber thoroughly is another logical step too. I know you've already done it, but dried cosmoline is real hard to get out even with boiling water. A bore scope should help you double check that.

[14sutten]

For cleaning the cosmoline what works best other than boiling water? Drill with shotgun brush? Any chemicals work too?

[willyj73]

Filing rough edges on an extractor harms nothing and actually helps if the extractor has edges that are too sharp. I've had one that was digging into the cartridge wall. Removed the extractor, and took a few strokes with a file. If you don't want to do it, that's your choice, but it is needed on some extractors.

[RazorBurn]

For cleaning the cosmoline what works best other than boiling water? Drill with shotgun brush? Any chemicals work too?

Hoppe's #9 and a shotgun bore brush on a drill helped me with one M27 I have that had a real bad case of "sticky bolt syndrome".

[kupMosina]

Hello, I bought a mosin and i can't close the bolt with round (without it roons smoothly). It feeds it into the chamber without issue, but cant rotate it more than a little bit. I removed the extractor but the problem is still there. I cleaned the bolt and receiver with WD40 but it didnt help. I can't buy go and no go gauge in my country. I have steel lacquered deco ammo, but i hardly think that this is the problem if it goes into chamber without problem.

[Junk Yard Dog]

Hello, I bought a mosin and i can't close the bolt with round (without it roons smoothly). It feeds it into the chamber without issue, but cant rotate it more than a little bit. I removed the extractor but the problem is still there. I cleaned the bolt and receiver with WD40 but it didnt help. I can't buy go and no go gauge in my country. I have steel lacquered deco ammo, but i hardly think that this is the problem if it goes into chamber without problem.

Possibly a small piece of a cartridge case up by the neck of the chamber is stuck in there? That or the headspace is too tight. Can you get another bolt head or bolt assembly in your country and see if that solves the issue? If it does then fire the rifle with it tied to an old tire and fired with a string on the trigger with you behind something solid pulling that string. Do that a few times and then have a look at the fired cases for signs of any damage. If no damage then you are probably safe. How about a stuck case extractor, can you get one of these even if you have to order it from outside your country?