Ruptured 7.62X54R Casing?

[RedCable]

I had one ruptured case out of 40 PRC surplus rounds fired from my newly acquired SVT-40 should I be concerned with the rifle or ammo?

 

[shredder]

Pics would help, amigo.
We won't be able to answer your question until we see the case in question.

 

[RedCable]

I meant to keep it, but I lost it. It's a hairline crack from the top of the case to about quarter of the way down to the bottom. If that helps?

 

[kennymo]

What do the other cases look like? Any flattened or slightly pushed out primers, any faint rings that might indicate potential head separation?
Was the case body split or is it just a crack at the neck?

 

[Far North]

The consensus here seams to be that the Chinese x54r is a little brittle. I have had maybe 1 in 100 have a slight crack at the neck when shooting it in my Mosin.
The size of the crack you mention sounds pretty big though. I would keep an eye on it.

 

[TimC]

I personally wouldn't panic unless it happens with all of your ammo. Some brass gets overworked and becomes brittle with age. Milsurp ammo powders can react to the inside of the cases, corrode and thin the case walls, this can cause case splits. Serious large splits can allow gas cutting n the chamber if unchecked. I had a batch of .223 Lapua in which 9 out of 10 cases split at the neck on the first firing! Bit of a sickener over the cost but the milsurp alternative worked fine, the brass turned out to be a batch that wasn't annealed properly if at all! A rupture is usually where an unsupported portion of a case (such as extracting the case before the round has left the chamber) actually blows a hole out of the case wall. Very rare in rifles, sometimes seen in some pistols but unlike case splits down to the weapon, its timing, setting up, loadings etc rather than brittle brass.
I had a 9.5 Manlicher Schonauer let a few cases go ahead of the rim, poor headspace was to blame but that was head separation of the brass or near separation which is also splitting. This can be seen often with brass flow at the neck if you are lucky!

 

[woodchopper]

I've had a few that did the same. Its mil surplus ammo its made to go bang and at the lowest cost, steel cases, not a lot of streach, and some will be at minimum spec.

not really a big deal to have case necks split from time to time.

 

[RedCable]

I kind of figured it might be that Chinese steel case surplus ammo. I'll be checking the headspace on my rifle anyway just to be sure, but from the sounds of it I don't think I'll find anything wrong.

Thanks everyone for your help.

 

[Caleb314]

My svt-40 and all my mosins do that on occasion it's nothing to be worried about. If it gets to be more then the neck splitting you might have a problem.

 

[marc_j]

The number of split cases is definitely proportional to age in Eastern European surplus. I had a small amount of 1946 which all split lengthwise from neck to base (pic). Some late 50's stuff I had split commonly. The stuff that is readily available now (1971 from Bulgaria - 71 10 head stamp) is pretty good. Rarely I get a small neck split in Mosins.

Fluting, used to aid extraction in the SVT inevitably leads to greater chamber wear. Gas is forced back passed the flutes and erodes the shoulder and body. Spent cases from a good chamber should have no soot marks that extend into the shoulder or chamber. If you have stripes extending into the body of the casing, then the wear is considerable. The casing on the left is from a good chamber; the two on the right are from a worn chamber. If you are buying an SVT all you should see is a smooth chamber and a flute ring at the neck. If you see stripes in the chamber, skip it or pay less.

Using the same ammunition I get many more case splits in my SVTs than Mosins. Judging by the spent cases left by others at the range, it is the same for them.
No cause for alarm. Wear safety glasses. Watch for any signs of further deterioration. The chamber is the pressure vessel, not the casing.

[/IMG]

[/IMG]

 

[Mumbles Marble Mouth]

I got some Chinese 7.62x51 for my Norinco M305 that all have a crack in the neck. Didn't notice until about 60 rounds later when I noticed a fired case on the bench was cracked from the neck down to the shoulder. Inspected the rest of the ammo and every neck has a tiny crack in it. I said, "@#$% it" and just kept shooting. If it reliably fires it and extracts it, I then I don't really care. I only have 40 rounds of it left and I'm just waiting for my .308 reloading dies and I'm doing to start reloading for the rifle instead of shooting crap like this.