Mosin Bolt Jam


November 12, 2012, 09:27 AM
My brother purchased two 1943 Mosin's and is having issues with both of them. When he fires the bolt will freeze and has to be pushed up with great force on one to eject the shell casing.

On the other rifle even if you can get the bolt up and back sometimes the empty casing has to be pushed out with a cleaning rod from the breech.

He has taken them both down from the wood, disassembled the bolts and cleaned them scrubbed and cleaned the barrels with butches bore shine and a brass brush and still the hanging bolt. Any suggestions?

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November 12, 2012, 09:38 AM
Clean more. Watch a few of the video tutorials on Youtube for Mosin "sticky bolt" syndrome. Its not uncommon.

November 12, 2012, 09:47 AM
Like the man said, clean it more............MN are notorious for having gummed up the bore doesn't do much if that chamber is coated with old crapped up lacquer left there by a lotta surplus lacquered rounds.

I'd suggest a good solvent soak and then followup with a good bronze shotshell brush chucked in a hand drill and ran at fairly low speeds......just be careful you don't let any of the steel center contact the chamber or bore.

My bet would be that those shells that have to be punched out are doing that because the extractor is overriding the rim............brings the question of pitting in that chamber but you gotta clean it before you'll be able to make that call.

November 12, 2012, 11:48 AM
Take apart the bolt.
Boil it in water for 15 mins

You have cosmo in your bolt from a crappy cleaning job.

November 12, 2012, 12:11 PM
As the others said, take the bolt apart, clean it, and clean the chamber. What ammo are you using? You might also try different ammo if you are shooting surplus. I have one box that makes the bolts on 3 different Mosins very hard to work. In all 3 guns, switching to another batch of ammo and the bolts worked great.

November 12, 2012, 12:50 PM
Avoid the 'green' laquered ammo. Always gave me trouble. I have five Mosin rifles - the 'copper-washed' and brass cased ammo has no such issues.
Also, wartime Mosins had roughly finished chambers - I have found polishing the chamber with a shotgun cleaning mop and fine polishing compound really helps. Don't remove any metal, just a good polishing/burnishing.
It's the roughness of the chamber that often holds the laquer as it softens from firing.

November 12, 2012, 01:11 PM
Also remember not to open it with your fingers. Use your arm and slap it up with the palm of your hand.

November 12, 2012, 02:55 PM
Look in the bolt lug recesses for cosmoline, too. It can get there and cause serious sticking. The failure to extract could be caused by gunk underneath the extractor. Knock it out of the bolt head with a punch and clean underneath it, then reinstall it.

Cosmoline dissolves quickly in mineral spirits.

November 12, 2012, 02:57 PM
I don't shoot milsurp in mine, it's either commercial SP or handloads, but I'd do the 20 ga brush/drill routine with laquer thinner...That stuff will disolve just about anything.

November 12, 2012, 04:29 PM
Cllean the chamber of cosmoline.

It can look bright and shiney, especcially if you have fired rounds.

A 20 gauge brush and some break cleaner will take the chamber cosmo out and down to steel.

Sticky/hard to open bolts are the Mosin's way of telling you to clean it. The cosmo protected it through 60 years of storage and can be hard and dry, gotta dissolve it.

Rail Driver
November 14, 2012, 04:08 PM
I agree with everyone else - clean more. You're not there yet.

November 14, 2012, 04:55 PM
I soak my chambers with clp once ever 100 or so rounds, you'd be surprised how dirty a "clean" rifle can really be

November 14, 2012, 05:07 PM
Cosmoline... Clean Well...Agreed.
It is very typical.

November 15, 2012, 09:38 AM
Thanks will pass on the info.

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