case head seperation?

straz · June 13, 2008, 02:17 PM

How do I know if a case head is close seperation? Are there signs I should be looking for?

Big Caliber · June 13, 2008, 02:46 PM

This may not be worth much but it did happen to me after reloading 7mm Rem Mag cartridges once too often...the cases showed no indication of anything odd until I started firing some test loads one day. The case came out of the rifle with the neck and shoulder still in the chamber. After a few more rounds did this, I decided that you can't load up 7mmRM brass more than 6 times. No harm done to me or the Browning A-bolt that I had at the time. I believe I was using Remington brass. Now that I think about it, a few cases did show slight tears in the mouth, but they went into the recycle can.

Shoney · June 13, 2008, 03:16 PM

Head Separation - Separation of the case head from the case body, caused by stretching of the brass, usually due to oversized chamber or excessive headspace. Also caused by cases that has been reloaded many times, with resulting weakening of the brass.
Headspace - The distance from the bolt face (when the bolt is closed) to that surface in the cartridge chamber which stops the case’s forward movement. For bottle-necked cases, the measuring point is centered on the shoulder and is known as the datum line. For belted magnum cases, the headspace is measured from the front of the belt to the head of the case. In practical terms, the amount of free movement a cartridge has in a closed chamber. This dimension is critical for the safety of the shooter, as well as the accuracy of the weapon system. Insufficient headspace hinders complete chambering; excessive headspace permits case stretching, separation or rupture, endangering the shooter.

If you go to Steve’s Pages, you will find some good pictures, especially the cutaway showing the paperclip tool.
http://stevespages.com/page8.htm
near bottom of main page go to Table 3
On Table 3 go down to Case Information and hit Diagnosing Problems

R.Childs · June 13, 2008, 03:45 PM

Straz, if you have a headspace/case stretching problem, you will notice a bright ring around your casing just forward of the rim or casehead. It will be above the webbing of the casehead. This is where the brass stretches. When the firing pin drops, it pushes the casing forward in the chamber till the shoulder of the casing bottoms out in the chamber. This leaves a few thousandths of an inch(.002-.006 Saami specs) between the casehead and the bolt face. This is known as headspace. As the firing pin pierces/ignites the primer, the casing expands from the pressure and actually "stretches" to fill in the space between the casehead and boltface. The more space there is the more the brass stretches. Most fluent reloaders will adjust their dies so when they resize, they will set the shoulder back a minimal amount(I set mine back .001" when I get hard bolt lifts). This reduces stretching and prolongs casing life.

Check your casings for the bright ring just forward of the case head. You can take jim clip and straighten it out and sharpen one end. Bend the sharp end 90 degrees and stick it into the casing. Let the sharp end scrub against the casing wall above the casehead and if a groove is felt, you will know your brass is stretching to an unsafe point and a casehead separation may result.

June 13, 2008, 02:17 PM	#1
straz Junior Member Join Date: May 1, 2008 Location: virginia Posts: 10	case head seperation? How do I know if a case head is close seperation? Are there signs I should be looking for?

June 13, 2008, 03:16 PM	#3
Shoney Senior Member Join Date: February 21, 2002 Location: Transplanted from Montana Posts: 2,311	Head Separation - Separation of the case head from the case body, caused by stretching of the brass, usually due to oversized chamber or excessive headspace. Also caused by cases that has been reloaded many times, with resulting weakening of the brass. Headspace - The distance from the bolt face (when the bolt is closed) to that surface in the cartridge chamber which stops the case’s forward movement. For bottle-necked cases, the measuring point is centered on the shoulder and is known as the datum line. For belted magnum cases, the headspace is measured from the front of the belt to the head of the case. In practical terms, the amount of free movement a cartridge has in a closed chamber. This dimension is critical for the safety of the shooter, as well as the accuracy of the weapon system. Insufficient headspace hinders complete chambering; excessive headspace permits case stretching, separation or rupture, endangering the shooter. If you go to Steve’s Pages, you will find some good pictures, especially the cutaway showing the paperclip tool. http://stevespages.com/page8.htm near bottom of main page go to Table 3 On Table 3 go down to Case Information and hit Diagnosing Problems __________________ I pledge allegiance to the Flag - - -, and to the Republic for which it stands….Our Forefathers were brilliant for giving us a Republic, not a democracy! Do you know the difference??? and WHY?http://www.wallbuilders.com/LIBissue...les.asp?id=111

June 13, 2008, 02:46 PM	#2
Big Caliber Senior Member Join Date: October 10, 2006 Location: S. CA Posts: 421	This may not be worth much but it did happen to me after reloading 7mm Rem Mag cartridges once too often...the cases showed no indication of anything odd until I started firing some test loads one day. The case came out of the rifle with the neck and shoulder still in the chamber. After a few more rounds did this, I decided that you can't load up 7mmRM brass more than 6 times. No harm done to me or the Browning A-bolt that I had at the time. I believe I was using Remington brass. Now that I think about it, a few cases did show slight tears in the mouth, but they went into the recycle can.

June 13, 2008, 03:45 PM	#4
R.Childs Senior Member Join Date: June 11, 2008 Location: S.Georgia Posts: 164	Straz, if you have a headspace/case stretching problem, you will notice a bright ring around your casing just forward of the rim or casehead. It will be above the webbing of the casehead. This is where the brass stretches. When the firing pin drops, it pushes the casing forward in the chamber till the shoulder of the casing bottoms out in the chamber. This leaves a few thousandths of an inch(.002-.006 Saami specs) between the casehead and the bolt face. This is known as headspace. As the firing pin pierces/ignites the primer, the casing expands from the pressure and actually "stretches" to fill in the space between the casehead and boltface. The more space there is the more the brass stretches. Most fluent reloaders will adjust their dies so when they resize, they will set the shoulder back a minimal amount(I set mine back .001" when I get hard bolt lifts). This reduces stretching and prolongs casing life. Check your casings for the bright ring just forward of the case head. You can take jim clip and straighten it out and sharpen one end. Bend the sharp end 90 degrees and stick it into the casing. Let the sharp end scrub against the casing wall above the casehead and if a groove is felt, you will know your brass is stretching to an unsafe point and a casehead separation may result.