I had my first case seperation .It was in my custom 300 ultra mag. Remington brass.This brass has only been fired twice. It was full length sized, bumping the shoulder. Not a hot load. It did have a extractor mark, unlike the other two shots I fired before this one. The rest of the case is still in the chamber. I tried to get it out using a pistol cleaning rod with a 416 caliber bronze brush . I could feel it as I brought the brush backwards, but it did not come out. I will have to take it to my gunsmith.
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Case Seperation 300 Ultra
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I had my first case seperation .It was in my custom 300 ultra mag. Remington brass.This brass has only been fired twice. It was full length sized, bumping the shoulder. Not a hot load. It did have a extractor mark, unlike the other two shots I fired before this one. The rest of the case is still in the chamber. I tried to get it out using a pistol cleaning rod with a 416 caliber bronze brush . I could feel it as I brought the brush backwards, but it did not come out. I will have to take it to my gunsmith.
gohring3006
Well-Known Member
The extractor mark is from the case head separating from the case and being slammed into the bolt face.. Two firings, that seems like something besides bumping the shoulders to far.
Sounds like the smith should check the head space too. I would cut a couple of the other twice fired cases open lengthwise to see how much the brass has thinned at the web. They are probably on the verge of separating also..
When you say bumped the shoulder back 2 thousand, was that with the initial loading of virgin brass? And then maybe didn't adjust the die after the brass fire formed to your (possibly longer) chamber?
dcederberg
Well-Known Member
I have been there, here is what worked once for me. Run a bore snake in until the brush clears the case mouth, then pull it backwards and many times it will pull out the brass. Good luck.
Ceder.
Ceder.
J E Custom
Well-Known Member
Case head separation Is caused by several things. It is normally associated with head space issues.
Excessive headspace, can be caused by the smith building in excessive head space when chambering. Head space should be held to a very minimum because of the undersized new brass
to minimize stretching it when initially Firing it. Case head separation normally starts on the first firing when head space is excessive weakening the brass in the beginning. Then every time it is "Over sized" the problem get worse until it fails.
I have found that Bumping the shoulder only improves the chance of this happening so I don't do it. If the brass starts to get tight, I size just enough to chamber. I also neck size only as long as the cartridge chambers to minimize working the brass any more than necessary. The use of bushing dies has also improved the brass life by cutting the number of sizing's by 50% if used correctly.
Every time you size the brass it expands to fit the chamber when fired, so the less you can work the brass the longer it will last with frequent annealing (Every 3rd or 4th loading).
Ejector Marks on the case head can be from over sizing (Increasing head spacing allowing the case head to slam into the bolt face) or from high pressure loads (Most common cause) a dirty/oily chamber can also cause this by increasing bolt loading.
Others may have different recommendations to prevent case head separations, but this works for me and it has been rare for me to get a case head separation.
Hope this helps
J E CUSTOM
Excessive headspace, can be caused by the smith building in excessive head space when chambering. Head space should be held to a very minimum because of the undersized new brass
to minimize stretching it when initially Firing it. Case head separation normally starts on the first firing when head space is excessive weakening the brass in the beginning. Then every time it is "Over sized" the problem get worse until it fails.
I have found that Bumping the shoulder only improves the chance of this happening so I don't do it. If the brass starts to get tight, I size just enough to chamber. I also neck size only as long as the cartridge chambers to minimize working the brass any more than necessary. The use of bushing dies has also improved the brass life by cutting the number of sizing's by 50% if used correctly.
Every time you size the brass it expands to fit the chamber when fired, so the less you can work the brass the longer it will last with frequent annealing (Every 3rd or 4th loading).
Ejector Marks on the case head can be from over sizing (Increasing head spacing allowing the case head to slam into the bolt face) or from high pressure loads (Most common cause) a dirty/oily chamber can also cause this by increasing bolt loading.
Others may have different recommendations to prevent case head separations, but this works for me and it has been rare for me to get a case head separation.
Hope this helps
J E CUSTOM
Easiest way is to purchase/invest in a good headspace gauge such as RCBS vernier gauge and learn how to set up your dies for minimal bump (if at all), by sacraficing some cases. Measure before and after dimensions and take imacculate notes.
Some simply neck size only until you find heavy bolt lift, that is the sign the case body is tight on chamber and time to resize.
During load development on a 25-06 I reused cases moving up in charges approaching max, I did this several reloadings on the same cases and eventually I came across those same cases, well luckily only got a small hole but wake up call that cases for load development are sacrificial and you need to take steps.. this reinforces that fact that resizing/bumping minimally is important as when they do get close its only minimal at worst or just strong sign of shiny rings.. Also, I came across some once fired 308's recently I was going to reload and by chance I lit up the interior and saw these rings, though no signs on the outside. Needles s to say they turned into scrap real quick. Be safe.
Some simply neck size only until you find heavy bolt lift, that is the sign the case body is tight on chamber and time to resize.
During load development on a 25-06 I reused cases moving up in charges approaching max, I did this several reloadings on the same cases and eventually I came across those same cases, well luckily only got a small hole but wake up call that cases for load development are sacrificial and you need to take steps.. this reinforces that fact that resizing/bumping minimally is important as when they do get close its only minimal at worst or just strong sign of shiny rings.. Also, I came across some once fired 308's recently I was going to reload and by chance I lit up the interior and saw these rings, though no signs on the outside. Needles s to say they turned into scrap real quick. Be safe.
jakelly
Well-Known Member
Pistol brushes don't work well for this.
You want a brush that's just a bit oversized. 8mm or 338 would be good, bigger isn't better.
A 338 bore snake might be the bees knees, sounds good, but I've never tried it.
In regards to why it happened:
Starting with virgin brass?
How are you measuring the bump? What tools?
*Somewhere in your rifle or set-up you are getting excessive headspace*
Are you bumping based off a tight case or once fired case? If you are using a lower pressure load, firing the case once might not give you an accurate starting point. Like JE said neck size one piece and fire it a couple times until it chambers tight, now you've got a real starting point.
You want a brush that's just a bit oversized. 8mm or 338 would be good, bigger isn't better.
A 338 bore snake might be the bees knees, sounds good, but I've never tried it.
In regards to why it happened:
Starting with virgin brass?
How are you measuring the bump? What tools?
*Somewhere in your rifle or set-up you are getting excessive headspace*
Are you bumping based off a tight case or once fired case? If you are using a lower pressure load, firing the case once might not give you an accurate starting point. Like JE said neck size one piece and fire it a couple times until it chambers tight, now you've got a real starting point.
I have a piece of barrel blank, that was reamed for my chamber. I use it along with a Sinclair bump gauge. I check my shoulder bump, twice. Cases were annealed after 2nd firing.
I have been reloading for 25 yrs. And I am very anal about my reloading. Do know everything,NO.
My gunsmith got my brass out of the chamber. He said he thought it's was just a bad piece of brass. He checked my head space on my action and said it was 2 thousandths. He looked and checked my reloads and said they were fine.
Thanks for everyone help.
I have been reloading for 25 yrs. And I am very anal about my reloading. Do know everything,NO.
My gunsmith got my brass out of the chamber. He said he thought it's was just a bad piece of brass. He checked my head space on my action and said it was 2 thousandths. He looked and checked my reloads and said they were fine.
Thanks for everyone help.
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I had a problem with cases separating a while back after 2 firings in a new rifle. The cases had unusually heavy reamer scarring not allowing the case to slide at all in the chamber when the case expanded upon firing, stretching the brass just above the extractor groove . I smoothed the chamber a little and never had another problem. The cases I was using had been fired a few times from other rifles so they here not going to tolerate much more stretching. Still, no more cases separated once the chamber was smoother.
To remove the brass I use a carefully sized E-Z out, that will not extend through the case neck, attached to a long 1/4 extention and reached through the action into the neck of the lodged case. Just takes a light turn of the E-Z out to dislodge it.
That's what happens when you were raised on a farm
To remove the brass I use a carefully sized E-Z out, that will not extend through the case neck, attached to a long 1/4 extention and reached through the action into the neck of the lodged case. Just takes a light turn of the E-Z out to dislodge it.
That's what happens when you were raised on a farm
