Case neck seperation

[USAF Marksman]

Anyone ever have a case neck completely rip off while full length sizing? This just happened to me in my Lee sizing die. The brass is once fired Winchester factory loaded brass that has been stored in a plastic bag since shot probably 5 years ago, then tumbled in corn cob media. It took a considerable amount of pressur to get the case in the die after using a lanolin based spray lube. Any ideas what I'm doing wrong or missing here? Never had this much trouble even sizing 300WM brass.

 

[Barrelnut]

Never had this much trouble even sizing 300WM brass.

I don't understand. That doesn't look like a 300WM case to me. Where's the belt?

 

[dok7mm]

A couple of things stand out as possible culprits. I am guessing the brass was stored in the bags without being cleaned properly and the corrosion from the powder did a job on your brass necks, being they are the thinnest part of the case. Second, a close look at your picture shows maybe you didn't get them as clean as needed, prior to resizing -- did you brush the inside of case necks and inspect ? If not, the expander ball pushed the neck down on the shoulder ( crimping it ????) and then on the upstroke finished the separation. Lastly, did you get enough lube inside the case neck for the expander to do it's thing. Even stored brass will age harden to some degree, compounding the other issues.

 

[USAF Marksman]

I guess I didn't word that last part right. It's a 243 case. I was just comparing the required pressure to the larger case.


The cases were not cleaned before storage. I had them saved from before I started reloading. They were tumbled recently, but that is all. If they deteriorated because of that, I can definitely understand. I gave the necks a couple of squirts from the spray bottle before sizing and did not brush them. Maybe all of those things, or a couple combined, caused the separation. I'm by no means an expert, and learning as I go. Needless to say those cases are in the trash.

Thanks for the input. Like I said, I have had any issues sizing any brass thus far. Figured I'd get the opinion of some pros before I laid any blame.

 

[dok7mm]

Not a problem. In fact, the reason I thought I recognized the problem was that I once did the same thing. The brass might have been saved by spinning a .243 bore brush in the necks and a polishing of cases followed by annealing, but like you, I trashed the cases and replaced them with new brass. That's how we all learned, in the old days. Good luck in your reloading and thank you for your service.

 

[Barrelnut]

Duh. Sorry now I get it. That is some serious green oxidation there inside the neck and on the table...

 

[dok7mm]

Duh. Sorry now I get it. That is some serious green oxidation there inside the neck and on the table...

Barrelnut, Don't feel so bad, I looked at the picture 3 times, before an old memory came back to haunt me. Green ain't good unless you can fold it.

 

[Gene]

I have done the same thing with spray lube. Now I use Imperial wax all the time, problem gone.

 

[MagnumManiac]

Have had this occur a few times with stored brass. The verdigris (green stuff) causes the brass to become brittle. Cleaning, then polishing before annealing generally corrects the issue.
I also use powdered graphite brushed into the case necks before sizing, if using an expander button type die, this helps immensely with the force required to drag the expander through, and, helps to minimise case stretching of the necks and shoulders.
Also, brass age hardens, even if it isn't stressed by having a bullet seated, just the fact it was 'sized' is enough to start the process.
Annealing will fix the issue.

Cheers.
gun)