The Firing Line Forums - View Single Post - 7.62x54R Case rupture. Headspace issue or ammo?

Gator Weiss · March 25, 2012, 09:21 AM

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.

March 25, 2012, 09:21 AM	#24
Gator Weiss Senior Member Join Date: August 13, 2007 Posts: 117	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.