Mosin Nagat BOLT will not close on an empty chamber

[Dr T]

Help.

When I was getting ready to go to the range this morning, I dropped the bolt of my M39 on the garage floor. It sprang apart.

After re-assembling the bolt, I discovered that the bolt handle would not close. In fact, it would only rotate about 15 degrees.

I can see no visible damage to the bolt, and the chamber and locking lugs look clean.

Any thoughts about what it was that I messed up and how I might fix it?

Thanks.

 

[highorder]

The Mosin bold will go together two ways; the right way, and the way you've discovered!

Try this:
http://www.youtube.com/watch?v=PBQ9EVlaRmo

and this:

http://7.62x54r.net/MosinID/MosinDisassembly.htm

 

[Dr T]

Saw those when I was trying to figure this out.

My problem is that if I have re-assembled the bolt improperly, I do not understand what I have done wrong.

It looks just like the picture.

Is it possible that the extractor may have gotten bent when I dropped it and it is binding on something? It is fitting a bit below flush at the bolt face.:banghead:

 

[Cosmoline]

Oh I doubt it. These ain't fragile rifles. To confirm--you have taken it apart and put it back together and that didn't fix it?

If you can post a picture that would be helpful.

 

[Dr T]

I have taken the bolt apart and re-assembled it several times to no avail.

I would take a picture, but I can see nothing amiss to take a picture of. The bolt simply will not close.

Right after the bolt was dropped, I reassembled, closed the bolt, and went to the range.

The first time I tried to chamber a round, the bolt would not close (while closing on an empty chamber). However, I did notice that the bolt was beginning to get stiff on closing.

When I got back home, I disassembled and reassembled the bolt.

Now it will not close at all.

I am sure there is something simple that is wrong, but the simplicity of the ac action is hiding something from me and I must be overlooking something obvious. Also, it may not be in the bolt per se, but I have examined the receiver and can see nothing blocking the lugs from closing.

Anyone run into anything similar (I have found a few mentions on the Internet of something similar, but no resolutions).

Thanks.

 

[Zack]

Please post a picture of it bult and taken a part in all peice with some angle pictures so we can look at it.

I have had a problem with mine before because I turned it the wrong way. Please post pictures of it built ( working order ) and taken a part.

 

[Dr T]

Zack,

Which piece was turned the wrong way?

Thx.

 

[courtgreene]

the butt end, i had the same problem on a friend's. you can line it up by turning it one way but it is technically upside down and needs to be turned the other way, 180 degrees. That was our problem anyway. they are right though, pics would help.

 

[Sebastian the Ibis]

If the bolt only closes half way:

Look at the flat band of metal on the underside of the bolt, is it straight with the notch lined up with the piece sticking out from the part above it? Or is piece sticking out not lined up with the notch at the end causing the flat band of metal bend down slightly?

 

[NCsmitty]

Here is a bolt disassembly/assembly for the Mosin. I hope it helps.

www.surplusrifle.com/finnishmosin/boltdisassembly/index.asp



NCsmitty

 

[Dr T]

Thanks. The more I look at it, the more I suspect that the problem is not in the bolt but in something else. The bolt looks like the one in NCSmitty's article.

Now if I could only figure out what the something else is. Maybe the Ejector?

 

[Janos Dracwlya]

I had a similar problem one time - the front screw on the magazine was too tight and part of the magazine was interfering with the bolt.

 

[Dr T]

Sebastian: I did that on an earlier iteration once. As far as I can tell, It is now correct and looks like the photo in the article (note that I did not completely disassemble the bolt: The firing pin was not removed from the bolt assembly).

Janos: Thanks for the suggestion. Tried various tensions on the action screws. No joy. But, it was a very good suggestion.

As an experiment, I inserted the bolt head into the receiver (without the rest of the bolt assembly). It would only turn as far as the sticking point (about 15 or 20 degrees) before stopping.

When I try to use the bolt handle to force the action closed, it springs back as if it is under spring tension.

From this I have (correctly or not) concluded that it has something to do with the races for the locking lugs. However, I have visually inspected them and inspected them by running the tip of my little finger around the races. However, what would cause the bolt to spring back?:banghead:

 

[NCsmitty]

I think it has to be the extractor out of position or bent and catching. That would give a torsion bar feel to the bolt handle.



NCsmitty

 

[Dr T]

I tend to agree. While the butt of the extractor is flush with the bolt head, the business end looks like it is bent inwards. This could have been bent when I dropped the bolt on the cement floor.

I will order a new extractor and go from there...

Thanks to all for your suggestions.

 

[Cosmoline]

I'm very doubtful you were able to bend the extractor just by dropping the bolt. It naturally is not flush at the end, it angles into the groove. It's under tension so it will grab the rim. Besides, if it's bent towards the pin, it will have no impact on anything until you try to chamber a round. It would take tremendous force to bend it outward. Tremendous. As in, with all my might it's tough to even bend it out enough to remove the extractor.

Please post a pic if possible. It's worth a thousand words in cases like this.

Hold on a second--have you used this rifle, or other Mosins before? It occurs to me that you may be stopping your push when the bolt encounters resistance, which happens normally about 15 degrees when you being to compress the spring back and lock the lugs. Try pushing harder.

 

[Dr T]

Sorry about the lack of pictures. My wife has absconded with my camera.

I went down to the neighborhood Gander Mountain and looked at the bolt head on a working MN.

Cosmoline, I understand your doubts about being able to bend the extractor by dropping the bolt, since it is a very stiff piece of spring steel, But by comparing it to the one on the functioning MN, I would say that the extractor is definitely bent. On the MN I looked at (that had a smoothly functioning bolt), the back side of the extractor was flush with the outside of the bolt head. On mine, the extractor is much lower--about the width of the rim around the outside of the bolt face (maybe 0.5 to 0.7 mm?).

 

[caribou]

Different extractors have smooth backs, arched or uneven backs and some are curved down, if looking at them while they are installed in the bolt.
If the bolt flew apart have you looked at the forked end of the bolt coller/cocking knob guide or the stud onthe bottom of the cocking knob? having those misaligned or bent will stop you from closing the bolt by binding from underneath if one or both tines on the "Fork" end are bent or broken.

 

[Dr T]

I recently picked up a 91/30 (1929 hex receiver, refurbished) so I have something to compare it to.

It is definitely the extractor that is causing the problem. I can insert the rim under the extractor and chamber and eject a cartridge. I have a couple of extractors, bolt heads, and some headspace gauges on order.

Then, I will first attempt to remove the extractor from the orginal bolt head and replace it.

Are there any specific hints for getting the extractor out (since Cosmoline implies it is a chore)? I do have a vise, a new 1 lb. brass hammer and a new set of brass punches.to use. If the extractor replacement is too big a pain, I can just hope that one of the new bolt heads will headspace properly.

Any suggestions?

 

[NCsmitty]

I would suggest revisiting the surplus rifle site and review the tutorial, and proceed with removing the extractor. Then check the headspace before reinstalling the new extractor.
Remember to pad the vise, and common sense will guide you.



NCsmitty