Case head separation query

[UndFrm]

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

 

[ClayM]

Could the marks be from the ammo box, riding to the range and back?

 

[SecondsCount]

Do you measure how much you bump the shoulder when sizing?

Could it be something in the chamber?

 

[Kracken McGraw]

Could the marks be from the ammo box, riding to the range and back?

I’m with you, empty brass riding case mouth down.

 

[Straightshooter1]

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

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):

 

[rwj]

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

I suggest using a dental style pick for detecting separation. Inexpensive ($5) at Harbor Freight. They’ll “catch” on really small cracks that a paper clip may bridge over.



Cases are inexpensive compared to the potential damage separation during firing can cause. Being early in your hand loading journey, I would set them aside…

 

[jelenko]

Yeah. Those lines are right where I've gotten case separation.

If you've dragged the end of a paper clip inside over where the lines are and felt nothing, there isn't anything. Like others said, maybe from riding in an ammo box.

Another way to test is to shine a light into the mouth of the case to see if there's a line on the inside.

Yet another way would be to load one case and fire it. If those lines are from incipient case separation, the next firing should absolutely separate it.

 

[Martin52]

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?

Your borescope should detect the line inside the case, if it's actually present. If you think the case is too dirty I'd give a few sample cases a good clean and try again failing which sacrifice one case and cut it open like the pic in Post #5.

 

[ELR LVR]

I happen to make and sell a tool specifically for that, checking the impending separation
there does not have to be a sharp line the tool hooks on
it is more you will feel an indentation in the area just above the thick web
Circled in pic
This is where the case stretches over time moving forward on each sizing and you keep triming it
OR- just headspace is too long so it stretches there at the weak link
---
My tool has great sensitivity to this indent and works really well
paper clip is ok but is too springy to feel with sensitivity
---
I used to use a paperclip
then got a case head separation at a match and threw my score
so I began making and selling these
Helps a lot

 

[hoz53]

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

i would sacrifice one and grind a hole in the side to look if you cant find anything else causing them

 

[William Vogel]

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

It looks to me like markings left from the chamber. There’s several lines on each case that all align on each piece. I’d scope the chamber for the lines. Also, why are the necks of the middle and right cases deformed? The case mouth is smaller than the rest of the neck.

 

[kelbro]

Could also possibly be an artifact of your sizing die.

 

[Syncrowave]

Another way to test is to shine a light into the mouth of the case to see if there's a line on the inside.

Another way I've used is to get a small white LED (small enough to fit into the primer pocket of a decapped case), hot-glue it to the end of a ballpoint pen barrel, wire it to an old discarded dongle transformer, then put it into the primer pocket and look down into the case mouth. Incipient case head sep will show up. (This is just a quicker and visual, method of checking cases, as opposed to the slower tactile paperclip method.)

But as someone else said, if you don't feel anything with the paper clip, you're probably OK.

 

[SeabeeKen]

I've got a 250 AI that marks cases that way. Not a case head separation but a chamber anomaly in my case. The company that chambered my barrel didn't clear the chips often enough and the reamer dragged chips around with it, cutting grooves and leaving marks like that on the brass. Case head sep will occur closer to the case head. feel for a groove on the inside.

 

[NorCalMikie]

Yet another way would be to load one case and fire it. If those lines are from incipient case separation, the next firing should absolutely separate it.

And if you're smart, you'll invest in some "broken case extractors". I have them for every caliber I shoot.
The cause is usually from excessive case sizing. Case too small for the chamber, gets fired and stretches to fit the chamber again. Resized back down (too far) again and you're getting close to junk cases!!

 

[6.5 forever]

It looks to me like markings left from the chamber. There’s several lines on each case that all align on each piece. I’d scope the chamber for the lines. Also, why are the necks of the middle and right cases deformed? The case mouth is smaller than the rest of the neck.

As distinct as the case marking is, I think a bore scope would show a imperfection in the chamber if that's the problem.

 

[divingin]

I suggest using a dental style pick for detecting separation. Inexpensive ($5) at Harbor Freight. They’ll “catch” on really small cracks that a paper clip may bridge over.

If you cut the end of the paper clip with a pair of precision wire cutters (or normal dikes, I suppose) at and extreme angle, you'll get a decent point to probe with. Cut before bending, as it's easier. You can make a *lot* of paper clips for the price of one dental probe.

 

[wkdickinson]

Those marks look way to far forward on the case to me a head separation. Any case head separations I've ever seen have always been just ahead of the case head. My guess is it is either the chamber of something like the ammo box. But I think if I were you, I would saw one in half longitudinally and look inside.

 

[358WCF]

If you cut the end of the paper clip with a pair of precision wire cutters (or normal dikes, I suppose) at and extreme angle, you'll get a decent point to probe with. Cut before bending, as it's easier. You can make a *lot* of paper clips for the price of one dental probe.

Ooohhh, an even quicker method for a point. The point helps with feel. I touched my clip end to a bench grinder to make a point. Been using it for a long time & it still works perfectly. Hangs from a small nail in easy reach.

It really does look like marks from the cartridge box in the OP.

 

[M-61]

The cause is usually from excessive case sizing

Yes
And I’ll include ‘shoulder bumping’. Which has become very popular with absolutely no idea what that does. ( aside of course when it is necessary).
Actually I’m surprised that there isn’t a lot more case separations since ‘bumping’ has
Seem to become a STEP in case preparation.
There are many thing’s happening in the chamber when the firing pin hits the primer.
Almost, but not quite, simultaneously.