7.62x54R Case rupture. Headspace issue or ammo?

The spam can prevents air from getting to the ammo and preserves it from rust or corrosion on the outside. But if the powder was not handled right, the corrosion comes from acid inside the cartridge case, and the outside packaging doesn't affect that at all.

On a slightly different subject: At one time, sellers of ammunition used to advertise ammunition with corrosive primers as "non-corroded", hoping the buyer would read that as "non-corrosive". If asked, the seller would say that the ammo was bright and shiny, with no sign of corrosion. But the same would not be true of a rifle barrel after firing his corrosive primed ammunition.

Jim
 
I don't agree that splits like the OP experienced are OK. I have seen chambers burned through splits like these. I would change the brand of ammo and bury the errant ammo.

Also, if ammo is stored in extreme hot and cold conditions, the necks can crack even in a tin container. This is called a season crack and happens because the necks are stretched back and forth over the bullet. I got a 1400 round case of 7.62x25mm Tokarev ammo and they were all cracked when I opened the spam cans.

Doug
 
I've fired a variety of current factory ammo such as S&B, Privi and Wolf without issue. This ruptured case came from a pack of gun show el cheapo, string-and-paper-wrapped ammo.
I do have a spam cam sitting here unopened... maybe I'll crack it and give it a whirl.
 
You need to examine the other cases you fired.

Examine the other cases that you fired for irregularities. These cases can show you signs of a chamber problem, head space problem, chamber erosion, and they can show you signs of brittle case necks, cracks and splits, etc, etc. If there are no irregularities of any kind observed in the other 39 cases you fires, then it was probably a problem confined to that particular casing.

You mentioned paper wrapping and twine. I am hoping that you did not try to shoot preservative / cosmolines out of the bore without cleaning the rifle! Case head pressure can climb enormously and this is not a good idea. I have seen it done by beer guzzling morons at a public gun range (they were ejected) who said they do it all the time. Never try to do that. Always there must be a very clean rifle.

The 7.62x54R is a very good cartridge. That large rim leaves plenty for an extractor to grab hold of and pull out of a dirty chamber. The taper in the case allows for easy chambering and easy extraction in a machinegun or a rifle. It was a well engineered case. It headspaces from the rim. Not from the shoulder. that is something to keep in mind.

Understand this particular case is not always made of very thick stock. Often this case was produced on over-worked and under maintained forming equipment. At times this ammo was produced in the third world by disgruntled political prisoners working for no pay. The density of the case material varies. The material alternates between brass and steel of varying thickness and quality. There will be a massive amount of pressure inside that case when it fires. ANYTHING COULD HAVE HAPPENED.

Your best bet is to examine your other 39 cases and go from there. If you have any of that ammo left, examine it closely before you fire it. Come back here and tell us what you find.
 
Opened up a can of Russian and the ammonia smell hit me first.Powder had broke down and ate through the case walls on some of the cartridges.
 
Nothing wrong with your rifle. It's the ammo.

Those commies were cheap bastards. They cut corners to extremes on production. The steel in those cases was extruded too far without being annealed, and it developed longitudinal weaknesses. If you closely examine a few dozen unfired rounds out of that spam can, you'll probably find several other rounds with the beginnings of cracks showing. If you closely examine all your fired rounds, you'll probably find several others that have cracked. That is very common. It happens to me all the time. The only noticeable problem from it is that the bolt can be a little sticky on the cracked cases. If it scares you, don't shoot any more steel cased commie surplus ammo.
 
yup prob the ammo....you'll notice this with 70 year old turk 8mm mauser ammo too! heck sometimes the case will already be split before you shoot it lol
 
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