bright ring marks on cases
- Thread starter rifleman
- Start date
enfieldspares
Well-Known Member
No I don't think so. Most full length dies DO NOT in fact full length resize to original CIP or SAAMI case dimensions. They resize down to just about above the web at the base of the case. Where the case becomes solid. And to a little bit bigger than CIP or SAAMI dimensions.
Obviously this never expands. But the rest of the case does. Over time they will be a marked difference in the colour of part of the case that the die has touched, and thus polished as it were, and the web that has not been touched. And so remains dull.
So whilst, yes, the body of your case may now be bigger than the solid web it is perfectly safe. (Well one hops so - I don't know what your reloads are).
SMALL BASE full length dies however will resize smaller for use in pump action and self-loading rifles.
A good standard safety test is to fire AND KEEP two factory loaded cartridges. Measure the base diameter just above the solid web area. You reloads from the rest of the same cases after reloading firing should have the same base diameter just above the solid web area.
Why? Because although brass expands and contracts to obturate it doesn't in fact fully contract back down to how it was when the cartridge was originally made with a new case.
And, unless you are using SMALL BASE dies when you reload it your full length dies won't size it down to that original size either. Thus the ring.
All this assumes you've got safe reloads BTW!
You will get these symptoms of course if your reloads are unsafe. But not a "ring" that is like it is "polished" but like a ring that is absolutely bright like the metal has been swaged down.
But I hope at least it explains why you will see them with safe reloads. A "polished" ring that still has the usual dimples and pimples as on the rest of the case exterior is OK. But a totally smooth swaged bright ring isn't!
Can you post a picture of a once fired factory round that you've resized (after use in your rifle) and a fired reload that you've sized (after use in your rifle)?
Also, of course, an oversize chamber even with a round at safe pressure will show this tendency to appear swaged down when full length sized.
A picture and the check on the base diameter is the best idea.
Obviously this never expands. But the rest of the case does. Over time they will be a marked difference in the colour of part of the case that the die has touched, and thus polished as it were, and the web that has not been touched. And so remains dull.
So whilst, yes, the body of your case may now be bigger than the solid web it is perfectly safe. (Well one hops so - I don't know what your reloads are).
SMALL BASE full length dies however will resize smaller for use in pump action and self-loading rifles.
A good standard safety test is to fire AND KEEP two factory loaded cartridges. Measure the base diameter just above the solid web area. You reloads from the rest of the same cases after reloading firing should have the same base diameter just above the solid web area.
Why? Because although brass expands and contracts to obturate it doesn't in fact fully contract back down to how it was when the cartridge was originally made with a new case.
And, unless you are using SMALL BASE dies when you reload it your full length dies won't size it down to that original size either. Thus the ring.
All this assumes you've got safe reloads BTW!
You will get these symptoms of course if your reloads are unsafe. But not a "ring" that is like it is "polished" but like a ring that is absolutely bright like the metal has been swaged down.
But I hope at least it explains why you will see them with safe reloads. A "polished" ring that still has the usual dimples and pimples as on the rest of the case exterior is OK. But a totally smooth swaged bright ring isn't!
Can you post a picture of a once fired factory round that you've resized (after use in your rifle) and a fired reload that you've sized (after use in your rifle)?
Also, of course, an oversize chamber even with a round at safe pressure will show this tendency to appear swaged down when full length sized.
A picture and the check on the base diameter is the best idea.
doghound
Well-Known Member
A bright ring above the web at the base indicates stretch I believe. Your rifle may have excessive head space and any full length case resizing die is going to reduce the case length again. Eventually this area becomes work hardened and will be pulled of by the bolt extractor.
Try getting a neck resizing die, dont run it down so it pushes the shoulder back and use once fired brass from you own rifle. It should cut down the case body stretch.
Take the normal pressure precations.
Try getting a neck resizing die, dont run it down so it pushes the shoulder back and use once fired brass from you own rifle. It should cut down the case body stretch.
Take the normal pressure precations.
THANKS DOGHOUND AND ENFIELDSPARES FOR THE REPLYS I WILL TRY AND GET SOME PICTURES OF SAID CASES IF ICAN GET SOME HELP FROM MY SON WHO IS A MORE CONFIDENT COMPUTER USER THAN ME , IHAVE A NECK SIZE DIE BUT NOW I HAVE CHANGED RIFLES I NEED TO START AGAIN AND FUUL LENGH RESIZE THEM ALL 
This thread has some good points regarding incipient case head separation v sizing marks.
http://www.thehighroad.org/archive/index.php/t-324062.html
Hope it helps.
Rgds Ian
http://www.thehighroad.org/archive/index.php/t-324062.html
Hope it helps.
Rgds Ian
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