A litle different Mosin sticky bolt problem

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offthepaper

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I've bought another Finn M39 (a '42 SKY). I've cleaned the metal, disassembled the bolt, cleaned the cosmo from everything and reassembled. Clened the residual cosmo crud from the chamber (I 'v done this with my other Mosins, so I know how important it is to get the chamber very, very clean to prevent the dreaded sicky bolt syndrome., But when I dry fire the rifle, the bolt is very hard to cycle, but once the trigger is pulled the action is very smooth, smoothly cock the bolt and pull the trigger and the bolt is hard to cycle again, Remember, there is no rounds being fired (yet) just dry firing for functional check.

Any ideas?
 
Mosins most defiantly don't have a trigger pack. the trigger rocks the sear, which just happens to be a spring.

Since the mosin cocks on the up stroke of the handle, it has to do with something dragging, that would be the back of the bolt, so that should be it. Most likely you are either encountering a heavy spring or just the regular 21lb spring when you cock the rifle.

Take the bolt out and manuall rotate it to the cocked positon, look at the recieve for drag marks.

Your description is difficult, are you recocking the rifle, cycling an already cocked bolt, or cocking and cycling the bolt.?
 
Your description is difficult, are you recocking the rifle, cycling an already cocked bolt, or cocking and cycling the bolt.?
Click to expand...

Cycling a already cocked bolts works smoothly, no problem. it's when I dry fire a cocked bolt that it gets very stiff, as I try to recock the bolt.
When the bolt is cocked, there is no stiffness at all to the action. It's only after I fire and try to recock the bolt that it's stiff. As I alreay posted, I have cleaned the chamber almost beyond clean. So, It's not the usual "crud in the chamber" issue.
 
Cocking the bolt takes a little effort as you are working against the mainspring. Is this an unusual amount of difficulty compared with other Mosins?
 
[/QUOTE]
Did you dismantle the bolt completely and scrub it all real good, then re-lube everything?
Click to expand...

Yes, I cleaned it very good.

Cocking the bolt takes a little effort as you are working against the mainspring. Is this an unusual amount of difficulty compared with other Mosins?
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Hi Cosmo, Yes, it is an definite difference, much stiffer than any of my other Mosins. I have 4 Finns and about a dozen other Mosins, and this is a definite issue with the recocking of the bolt once the spring has been released by dry firing. It's not that I cant recock it or have to beat it with a hammer, but the amount of force to recock the bolt on an empty mag and chamber is substantial, 5-10x the amount of force on any of my others.

ummm its a very old millitary bolt action...i think ive solved your problem
Click to expand...

I think i can safely state that's not the problem. ;)
 
mine does that too and i believe it's normal. IMO it's the striker that needs recocking and catch on to the sear. Once you fire, the striker and the rear assembly move forward, correct? - (you can see the rear tang screw). But once you rotate the bolt handle outward, you are recocking the rifle and you can't see the screw anymore. The pulling of the bolt is to clear out the empty shell, but you only need to rotate the bolt handle outwards to re-cock.

Hope that helps

edit: just saw the reply above, i think there may be some resistance in the bolt group. you can probably take it apart to check for cosmoline or corrosion/ rust.
 
Look at the cocking surface and compare the spring against another mosin, also, have you swapped out the bolt yet? If the bolt has the same problem with another mosin, then you know that it's the bolt, if the same problem happens with another bolt, then its the gun.

If it isn't the gun, look at the part when you completely disassemble the bolt, especially the load bearing (smooth and shiny) surfaces on the rear of the bolt body and cocking knob.

Also is it a constant force to get cocked or is it a single heavy spot then a release? If the second check the mating surfaces for pitting that you would have to overcome.
 
Here's the test I'd do. See how difficult it is to engage the safety. If it's extremely difficult compared with other Mosins, then your problem is the mainspring being extra stiff. If it isn't then the bolt is getting resistance when being cocked, probably from part of the trigger sear or bolt stop that isn't dropping down easily for the bolt head to pass over.

Also make sure your pin isn't screwed in too far and that you have proper extrusion.
 
But, did you take the bolt completely apart?
Click to expand...
Yes, I took it apart, cleaned it with mineral spirits, lubed with oil and reassembled. There is no cosmolene left in the rifle. The chamber was cleaned with MS also, as was the stock, barrel, trigger assy/mag, and hardware.
 
that is why I said, remove the trigger pac; yes I know it is not a complete in the thingy assy., just remove the trigger parts, put back in bolt, and cock and recock. you will then know the prob lies within the bolt.
It could also be a slightly bent, sear arm, or I call it the see-saw part, on a mosin.
I have a mosin 38, that is super clean, and oiled all moving parts with molyfusion, cocks super easy, and the bolt? well, if you unlock it from the chamber, and tip the bbl upwards about 20 degrees, the bolt slides by itself back to the rear, with a very satisfying "Sccchhhnnniiiiiiiiiiiiiiiiiiiiiiick!"
So schwing.
 
Locate the part of the bolt that cams the striker assembly back when the bolt is opened, and lubricate those surfaces with some really good grease. That may help.
 
As benEzra mentioned, check the Mosin bolt cocking cam for wear or galling.
Mauser cocking cams can suffer similar symptoms if overheated in a bolt bending operation with a resulting loss of temper.


NCsmitty
 
you have spare mosins, trade out the bolt and see if it still has the problem, try the bolt in another rifle. If it's the bolt, look for damage on the gliding surface (wouldn't call it a cam) compare it to another mosin bolt that works and look for the differences.
 
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