Mosin Nagant split case

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wabaf

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Hi I have a question about my moist nugget. Last week I was shooting surplus x54r, can't remember the country of origin but it is the steel core with painted silver tip. After a few dozen rounds, I got a face full of blue smoke, didn't burn or injure me in any way but it was a bit unnerving. I don't have a pic of the case but it was split from the rim all the way to the top or to the neck at least. Is this a safety issue? Is it a problem with my rifles headspace or just the quality of the ammo?
I have had a few split cases with that lot but not as bad as this one.
 
Oh and another question, with the same rifle sometimes when I am cycling the bolt and firing as fast as I can, the bolt doesn't ####. Why would it do this? It's #### on open so I don't understand how the action of me chambering a round and closing the bolt decocks it.
 
Do all you cases split or just the odd one? If they are all splitting I would have the rifle checked out by a gunsmith.
I am shooting Chinese surplus from my mosin and sometimes I get the odd one cracking around the shoulder or neck but from what I read the Chinese surplus is sometimes a little more brittle.
 
Check your headspace. The device to do it is super cheap.

That said, I have had several of these rifles and used most of the common surplus ammo. They all split some necks. I have never had any blowback from it though.

It should be really easy to tell if the rifle is "cocked" as the bolt is in a completely different position. The only thing that I can think of is that the bolts not being caught on the sear. Is the trigger typically super light? If its just barely engaging that could be a safety issue. Are you holding the trigger down while closing that action?
 
It's the odd case that splits, I shot a couple hundred that day. I'm not holding the trigger when it decocks on closing, it only happens when I'm shooting and cycling the bolt fast. The trigger doesn't feel that different from other mosin I've handled and it's not super light
 
wabaf said:
Oh and another question, with the same rifle sometimes when I am cycling the bolt and firing as fast as I can, the bolt doesn't ####. Why would it do this? It's #### on open so I don't understand how the action of me chambering a round and closing the bolt decocks it.
Click to expand...

I could be wrong but IIRC it's #### on closing
 
As others have said, a few case splits are normal. New (1970s) ammunition has few cases and less severe splitting than older ('40s) production. This is probably the result of a combination of steel quality (cleanliness) and a phenomena known as "ageing". Ageing results from very slow recrystallization of strained steels and migration of impurities to grain boundaries. The occasional split is not a cause for concern but like every risk, the chance of a more serious problem increases with exposure. I avoid very old ammunition as a general rule.

Check the shape and alignment if the sear spring for the de-cocking issue. Several of the Mosins I have got in cosmoline have had this issue. The sear spring should be straight (flat) - it should not have any bends

I posted pictures of a bent sear on page 33 of :M44 Collectors Source" in "Red Rifles".
 
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The Mosin Nagant bolt is #### on opening. When you close it the bolt should remain cocked by the lug on the bottom of the cocking piece coming into contact with the sear. If that contact is not happening, the bolt will uncock as you close it, and the firing pin will be protruding, and thus be in contact with the primer. If you closed it very quickly and with enough force it might strike the primer hard enough to cause the round to fire. This is not a safe rifle. I would be getting it checked out.

It might be that somebody shortened the sear in an attempt to lighten the trigger, and did so in such a way that it does not engage with the cocking piece lug reliably upon closing. In any case, get it checked out!
 
The second question is most likely you pulling the trigger as you operate the bolt. That, like the occasional bad case with "milsurp" ammo, is normal when shooting fast. Takes practice to get it right.
A painted silver tip is Czech.
 
I have lengthwise cracks occasionally at the neck from Bulgarian surplus. Most of that is just from case production and is not harmful.
 
the11 said:
The Mosin Nagant bolt is #### on opening. When you close it the bolt should remain cocked by the lug on the bottom of the cocking piece coming into contact with the sear. If that contact is not happening, the bolt will uncock as you close it, and the firing pin will be protruding, and thus be in contact with the primer. If you closed it very quickly and with enough force it might strike the primer hard enough to cause the round to fire. This is not a safe rifle. I would be getting it checked out.

It might be that somebody shortened the sear in an attempt to lighten the trigger, and did so in such a way that it does not engage with the cocking piece lug reliably upon closing. In any case, get it checked out!
Click to expand...

Obviously I did not recall correctly.
Beg pardon and I stand corrected, sir.
 
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