Help with Mosin-Nagant Sitcky Bolt Syndrome

[NRA1945]

The bolt on my Mosin is sticking after I dry fire it. It get more and more difficult to open the bolt as I dry fire it more and more, to the point where I can barely get it open even with much force. I've checked various sources with how to fix this problem but most seem to involve issues with firing live ammo or chambering rounds. Mine is sticking just with dry firing with no rounds in the chamber. I've heard that there may be hardened cosmoline in the chamber so I will try to clean this out, but I can't imagine this could be sticking that badly just from that, as my chamber doesn't seem to look so bad.

Any advice on how to fix this problem?

[Sonny]

Mine also has a sticky bolt but only after I fire about 10-12 rounds throught it.When it's cleaned and empty it cycles like a charm.

Yup it has me stumped but then I'm new to mosins.

[wingspar]

I had this exact same problem with one of my Mosins. The fix is easy. Disassemble the bolt. Then polish the surfaces in the two areas I have red arrows pointing to in the photo below, then apply a light coat of grease, and reassemble. Should be nice and smooth after that.

[Sonny]

Thanks wingspar..

Will definetly check out my bolt.

[WeldonHunter]

The first step before you start polishing things is to simply apply some grease to contact spots and shoot the rifle some more. These rifles are made from parts that were on other rifles so though they aren't new parts they need to basically break in to eachother. Sometimes it's just that simple. When you start polishing things you're removing metal that would have normally just worn to where it wanted be in the long run.

[WeldonHunter]

Mine also has a sticky bolt but only after I fire about 10-12 rounds throught it.When it's cleaned and empty it cycles like a charm.

Yup it has me stumped but then I'm new to mosins.

I'll add something else to what might be the problem you're experiencing. It sounds like you might need to clean the chamber of that rifle a little more aggressively or it may be the ammo you're using. Some of the coatings on ammo like lacquer and polymers will cause the problem you're talking about. I also have had some problems with some of the older, 1940s, surplus ammo causing real bad sticky bolt. It was definitely the ammo in that case because it happened after about 3 or 4 rounds and as soon as a put different ammo in the rifle it was gone. You may want to use some 000 or 0000 steel wool wrapped around a 20ga bore brush with some Hoppe's #9 or other bore solvent to clean the chamber. Put it on a section of cleaning rod and use a drill to slowly clean the chamber taking care not to go to far in. You don't want to hit the rifling. That may help.

This is different than what the original poster's problem is. His might be cured by simply applying some grease to the contact points described above and not dry firing the rifle. He's not having the problem with rounds in the chamber so that rules a dirty chamber out almost completely. Remember guys these rifle cock on extraction and are not a modern rifle. They're old relics and were not designed like a Remington 700.

[Gunowner99]

Seems sensible, I will have to check mine out.

[InOmaha]

Check to make sure your firing pin isn't bent. I had one that was slightly bent on a 1943 wartime production refurb. Take it out and roll it on a level surface and it's easy to see. You may be able to straighten it out some to keep the pin from dragging inside the bolt.

[NRA1945]

Mine also has a sticky bolt but only after I fire about 10-12 rounds throught it.When it's cleaned and empty it cycles like a charm.

Yup it has me stumped but then I'm new to mosins.

I'll add something else to what might be the problem you're experiencing. It sounds like you might need to clean the chamber of that rifle a little more aggressively or it may be the ammo you're using. Some of the coatings on ammo like lacquer and polymers will cause the problem you're talking about. I also have had some problems with some of the older, 1940s, surplus ammo causing real bad sticky bolt. It was definitely the ammo in that case because it happened after about 3 or 4 rounds and as soon as a put different ammo in the rifle it was gone. You may want to use some 000 or 0000 steel wool wrapped around a 20ga bore brush with some Hoppe's #9 or other bore solvent to clean the chamber. Put it on a section of cleaning rod and use a drill to slowly clean the chamber taking care not to go to far in. You don't want to hit the rifling. That may help.

This is different than what the original poster's problem is. His might be cured by simply applying some grease to the contact points described above and not dry firing the rifle. He's not having the problem with rounds in the chamber so that rules a dirty chamber out almost completely. Remember guys these rifle cock on extraction and are not a modern rifle. They're old relics and were not designed like a Remington 700.

This problem is happening during dry firing. I haven't even actually shot the thing yet. Every time I cock the bolt, then dry fire it gets harder and harder to re-cock, to the point where I have to use considerable force to get it open. It moves as smooth as butter when it's already cocked. Is this normal for Mosin bolts?

[millman]

Have you put grease on the cocking cams? That will alleviate most of your problem.