I am having some issues with case rupturing during firing. I have been experimenting with forming 8mm Mauser and 7.7 Japanese cases from once-twice fired 30.06 cases. I annealed the neck and shoulders and visually inspect each case for defects however, out of the 60+/- cases I have formed, 7 (4 in the Arisaka, 3 in the M48) have ruptured about 1/8" vertical above the base. I was shooting .312 180gr over 38grs of H4895 (7.7 Jap) and .323 174gr over 44grs of H4895 (8mm). Does anyone anneal the entire case?
Ruptured cases
- Thread starter jr45
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rcmodel
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NO!!!!!!!!!!!!!!!!!!!! 
You will blow yourself up for sure if you anneal the case head area!
If you are experiencing case-head separation about 1/2" forward of the rim, you either have excess headspace in the rifles.
Or you are shoving the shoulders back way too far on the cases when you re-form them.
The other possibility is, the 30-06 cases you are using already have stretch rings from the first firing in a rifle with excess headspace.
Take a paper-clip and bend an L on the end of it. Then reach down inside the cases and feel for a stretch-ring at the location where they are breaking.
If you can feel a ring, the case is already toast!
rc
You will blow yourself up for sure if you anneal the case head area!
If you are experiencing case-head separation about 1/2" forward of the rim, you either have excess headspace in the rifles.
Or you are shoving the shoulders back way too far on the cases when you re-form them.
The other possibility is, the 30-06 cases you are using already have stretch rings from the first firing in a rifle with excess headspace.
Take a paper-clip and bend an L on the end of it. Then reach down inside the cases and feel for a stretch-ring at the location where they are breaking.
If you can feel a ring, the case is already toast!
rc
Thanks for the responses, I will not anneal the whole case. I am not having case-head seperation (I think), but having ruptures. All the problem cases had either a virticle crack or hole on the side of the case about 1/8" above the base after firing. I will check the formed cases for stretch rings (didn't think of that), recheck the sholders, and if needed, have the head space checked again. I do not have this problem with manufactured 8mm or 7.7 commercial brass.
rcmodel
Member in memoriam
Are all of them from the same lot of 30-06 brass?
If so, I would suspect bad brass to start with.
You might try some other make & model of 30-06 brass and see if you still have the same problem.
rc
If so, I would suspect bad brass to start with.
You might try some other make & model of 30-06 brass and see if you still have the same problem.
rc
MMCSRET
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I found that when I used Military 30-06 cases for forming my 7.7 that it worked better than commercial. I had a 5 gal bucket of FA 58 Match brass that I use, good results.
I do not know if they are from the same batch. I have a large bucket full of the brass from various manufactures I accumulated over time. I do know that 5 of the cases that ruptured were Remington-Peters...the other 2, I don't remember.
rcmodel
Member in memoriam
That right there might be
A Clue!
rc
A Clue!
rc
rcmodel
Member in memoriam
You don't need to worry about headspace if all you shoot in it is your reloads.
Just take the striker assembly out of the bolt so you can "feel" whats going on.
Then, keep adjusting the die to push the shoulders back until the bolt will just close on a case with very slight resistance.
That is as close to perfect headspace as you can get.
rc
Just take the striker assembly out of the bolt so you can "feel" whats going on.
Then, keep adjusting the die to push the shoulders back until the bolt will just close on a case with very slight resistance.
That is as close to perfect headspace as you can get.
rc
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