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

**44 AMP** · March 1, 2012, 11:42 PM

Being a rimmed case, the 7.62x54R headspaces on the rim. What this means is that as long as the distance from the bolt face to the back edge of the chamber (through the rim) is within proper tolerances the rifle has "correct" headspace.

You could have a jugged, or grossly oversize chamber but if the rim specs are right, you have proper headspace. There are many military rifles that have "excessive" chambers, except for the critical headspace dimensions. After all, each case only needs to fire once....

However, this does not seem to be the problem with your rifle. The split case is typical of low quality ammo, especially after it has aged a bit. All it means is that particular case had something less than perfect QC during its manufacture. Could have been a flaw in the metal, or in the annealing process. Sometimes, its only a case here and there, sometimes it the majority in a particular batch.

Combloc milsurp ammo is not noted for its high quality control. Toss the case, and clean the rifle. Always, Always ALWAYS wear shooting glasses. Even when shooting the "good stuff".

March 1, 2012, 11:42 PM	#8
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,846	Being a rimmed case, the 7.62x54R headspaces on the rim. What this means is that as long as the distance from the bolt face to the back edge of the chamber (through the rim) is within proper tolerances the rifle has "correct" headspace. You could have a jugged, or grossly oversize chamber but if the rim specs are right, you have proper headspace. There are many military rifles that have "excessive" chambers, except for the critical headspace dimensions. After all, each case only needs to fire once.... However, this does not seem to be the problem with your rifle. The split case is typical of low quality ammo, especially after it has aged a bit. All it means is that particular case had something less than perfect QC during its manufacture. Could have been a flaw in the metal, or in the annealing process. Sometimes, its only a case here and there, sometimes it the majority in a particular batch. Combloc milsurp ammo is not noted for its high quality control. Toss the case, and clean the rifle. Always, Always ALWAYS wear shooting glasses. Even when shooting the "good stuff". __________________ All else being equal (and it almost never is) bigger bullets tend to work better.