Case head separation query

[K22]

No, don't fire them until you positively rule out incipient case separation. It is not worth the potential danger and damage.

Take one case, section it about 1/2 inch above the line with a hacksaw so you can clearly see if there is incipient separation (thinning in the area).

The paper clip method usually works but the dental pick is a better option. It may indeed be chamber or die marks. If so, 0000 steel wool polish might remove them. But if it was me, I would section a case to make sure before I used the remaining cases. I have seen cases that do not reveal incipient separation with paper clip method yet when sectioned, the inside shows a definite thinning in the area. This why I recommend you section a case.

If you are bumping the shoulder every time when it's not necessary, this will definitely cause excessive case stretching and eventually lead to case separation.

 

[ebb]

The marks look too far away from the case head to be separation to me, but I would do as Hoz has said and cut one open and look. My 6.5-284 brass has marks like these but it is from the plastic box. If you have the box these have been in you can see if the marks line up with the divider with all the holes in it.

 

[Pete Wass]

If you haven't watched Alex Wheelers video on finding your ideal case length, please do so.

 

[Doom]

Not pending case head separation but likely case separation. It is the result of resizing just like case head separation but stretching of the case body. It seems more likely to occur in AR style rifles but I've seen it in bolt action also..

 

[K22]

Not pending case head separation but likely case separation. It is the result of resizing just like case head separation but stretching of the case body. It seems more likely to occur in AR style rifles but I've seen it in bolt action also..

Yes, I've seen case separations in those approximate areas the OP posted. These were not head separations but case separations.

 

[47WillysGuy]

Fairly new to reloading so seeking expert opinion before I load these.

From a quick glance it looks like it might be. I ran a paper clip on the inside but unsure what I am looking for. The paper clip didn't catch/abruptly stop where the line is. I also used a borescope to see if I can see a line formation on the inside (idea from John), but I don't. Maybe it's too dirty to see the line?
These have been 8/9 times fired and were cleaned with steel pins before taking these pictures.

Ideally, I would chuck and get a new set of brass but I'll switch calibers after my barrel is done so holding off on that.

Should I go ahead to load these up?

Thank you

Hacksaw time. Sacrifice a case and dremel or hacksaw from neck topr

 

[Rick300]

Yes, I've seen case separations in those approximate areas the OP posted. These were not head separations but case separations.

Same here

 

[wkdickinson]

Contrary to what several people have posted in this thread, there is nothing inherently wrong with "shoulder bumping" and it in fact is often necessary. The key is measuring your fired cases (I usually measure 10 and use the longest as my datum), then set your die up to bump the should back a predetermined amount. I feel .0015" is enough in a bolt-action rifle (semi-autos probably .003"). I use a COAX press, so I only have to set the die up once and it is good for as long as I am shooting that barrel. With your die set up this way, you are likely not bumping the shoulder back every time, on every case, but rather only when the individual case is too long, otherwise the shoulder never touches the the die. The other big advantages of this is that you are not "overworking" your brass, so your cases last longer and the chances of a "head separation" are minimal.

 

[varget204]

It does looks like separation sign to me. Can you feel that line when you run your fingernail over them?

If you can feel it, then I'd say definitely separation about to occur and I'd trash them.

Here some pictures of some cases I had having case heat separation sings and one I cut open and show how my paperclip tool I use to feel the indentation the separation on the inside (it's not as sharp edge feel, but more a light feel that it's not running smoothing across the surface):
View attachment 1741113
View attachment 1741114 View attachment 1741115

if you make the end of the paperclip like a chisel & round it off similar to the curve of the case,it makes it easy to feel Recess or Crack, always check every case everytime, you can cull cases before resizing.I wrap masking tape around back of clip for a grip.Excessive shoulder bump can cause it and Hot loads will stretch cases

 

[Steve Donlon]

I measure every case and bump as needed with an adjustable body die as to avoid this I hope. With the AR, no body die but still measure every case and toss when in question usually primer pockets go first.

 

[M-61]

Contrary to what several people have posted in this thread, there is nothing inherently wrong with "shoulder bumping" and it in fact is often necessary.

I am one of those ‘several’ people.
There is everything wrong with shoulder bumping. As I stated it is done as a step by people that have no idea what’s actually happening. I noticed you incorporated the word ‘necessary’. As did I. I could have gone in to a long dissertation about semi auto’s, hunting rifles, etc. making bumping’ a ‘step’ in case preparation is inherently dangerous if you just Willy-nilly keep doing it for no reason.
Maybe the goal is to work the brass as much as possible with each reload and hope for the best. Some folks are lucky.

 

[M-61]

With your die set up this way, you are likely not bumping the shoulder back every time, on every case, but rather only when the individual case is too long,

Seems to be a version of what I wrote with the inclusion of “not bumping the shoulder back every time”.
Now you write about only bumping the shoulder when the case is too long.
Sounds good but no cigar. Should the ‘case’ be too long you trim the case.
This is where you have to know ALL the stuff happening when the trigger is pulled. The distance between the closed face of the bolt and the datum line won’t let the bolt close because the case has stretched. The distance between the closed bolt face and the datum line is called head space. What has moved? The shoulder of the case. No room. You ‘bump’ the shoulder back. Only when it’s needed.
I’m writing predominately about bolt actions.

 

[DShortt]

Where's fguffey when you need him?

 

[DShortt]

How about a datum gauge for the chamber, if we're really interested in rabbit holes?

 

[wkdickinson]

I am one of those ‘several’ people.
There is everything wrong with shoulder bumping. As I stated it is done as a step by people that have no idea what’s actually happening. I noticed you incorporated the word ‘necessary’. As did I. I could have gone in to a long dissertation about semi auto’s, hunting rifles, etc. making bumping’ a ‘step’ in case preparation is inherently dangerous if you just Willy-nilly keep doing it for no reason.
Maybe the goal is to work the brass as much as possible with each reload and hope for the best. Some folks are lucky.

Apparently you either didn't read my entire post or didn't understand it. I was very specific about what the purpose of "shoulder bumping" is and that it needs to be measured and done minimally. You say it's not "necessary", well use a neck die 4 or 5 times on a group of cases and see how many of them you can't close the bolt on. What in my post gave you the idea that I suggested doing anything "Willy-nilly"??? Everything require precision measurement.

The last line in your response totally mystifies me "Maybe the goal is to work the brass as much as possible...", because I specifically said if you bump the shoulder the way I suggested, you won't over work you brass! In your next post you talk about if you can't close the bolt then you need to trim the neck because the brass is too long - maybe, but we aren't talking about OAL here we are talking about base to shoulder length.

I honestly don't know why you decided to make this a pissing match. Controlled "shoulder bumping" is acknowledged by most everyone I read and respect as advisable if not necessary.

 

[209jones]

I sharpen the paper clips with a fine file, can really feel stuff with it then, operates kind of like the needle on a record player. I've felt the bump of a groove starting before the line showed on the outside of cases and got two more shots before it showed and I quit on them. Not recommending that practice, but, it does illustrate how fine a groove you can feel.

 

[M-61]

Apparently you either didn't read my entire post or didn't understand it

That’s it. That’s what must have happened.
I was just imagining what was written and typed furiously

 

[Orr89rocz]

When i got lines like that on my cases it was because the cases were sized too short.

Using the hornady comparator for the casing datum line, my fired cases were 1.620”. I realized the sizing die was setup to bump them back to 1.606”. I started to see lines in the case body when i started loading it hotter to find max pressure. On lower charges I didn’t see the lines. This was a die that was setup by my uncle on a wildcat of his that i inherited. I have since adjusted it out so the shoulder only moves .003 or so. I usually shoot for .003-.001. If i just neck size the bolt doesnt close silky smooth on the brass, so i bump it back a slight amount. Thought that was pretty common practice. Never had problems this way.

 

[charlie b]

I am a 'hacksaw' person. If I see something 'funny' with a case I cut it open. Cases are expendable, even Lapua

 

[dellet]

Just because it’s not necessary, does not mean it’s not beneficial.

Long before the buzzword phrase of “excessive shoulder bumping” became an internet sensation, it was called “ following the directions of the dies manufacturer”. The directions generally sized the case to minimum spec for the cartridge to fit in a chamber sized for maximum spec brass. Fully resizing the case to as new size. The problem is that “as new size” in a minimum chamber is often the leading cause of short brass life by losing your casehead.

Once people figured out that if they didn’t fully resize their brass, not only did case capacity went up, increasing velocity, accuracy but case life improved. All you had to do was set the die up to just, touch, kiss or bump the shoulder. It didn’t need to be pushed back where it came from, only reminded not to go any further.

The problem with just bumping the shoulder with an off the shelf die, is that the base is no longer fully resized. Which if ignored, will lead to another internet sensation called a “clicker”.

Clickers are evil and can happen for a couple reasons. Often because you can’t just bump the shoulder and resize the base at the same time. That mostly needs a custom die matching your chamber, or the nearly outlawed practice of neck sizing only. Here we should probably split clicker into two different categories or call one a clacker.

If a clicker is because a case head is too fat, a clacker is because the body is too long. Both can make the bolt hard too rotate. To know which you have you have to be able to distinguish between a clicker and a clacker.

The cure for clickers and clackers is the same. Apply more sizing. But be careful not to apply too much resizing, remember you just need to bump the shoulder, not push it. Because if you push it too much and too often, you can lose your head. I mean case head. Which you probably deserve to have happen anyway because, anyone who has their head stuffed up under their body at the opposite end of their neck and shoulders has an obvious problem.

So here’s the dilemma , many of the really experienced guys that shoot really small groups and or high scores, recommend full length sizing and minimum shoulder buzzword. This is absolutely impossible with a single off the shelf die. To get the base, the shoulder is in the wrong place, too much headspace when chambered. To size for minimal headspace, the base may not chamber or extract easily because it’s too fat.

Bottom line is that what we really need is a new buzzword for squeezing the case head down to a smaller diameter. Choke your casehead probably won’t work, maybe hug?

Things were so much easier when people reloaded to save money over factory ammo. Once people wanted better accuracy, it required the adaptation of buzzwords. Next thing you know there will be some of those confusing acronyms.