[qajaq59]

When I went thru my twice fired .308 brass yesterday I found that 5 cases out of 100 had split in exactly the same place on both sides of the neck. Then after I ran the others through the tumbler and sized them, I noticed that the Lee dies had scratched them all around the neck, much like you'd find around the outer rim of a coin. They are tiny,tiny scratches and hard to see, but if you run your nail over them you can certainly feel them.

Now my guess is that that's likely why the cases necks split so perfectly on all 5 cases. I've had plenty of cases split over the years, but never 5 in exactly the same way. They looked like someone has actually measured and cut them.

Have any of you people had this happen?

I wrote Lee about it and I'll be curious to see what they know about it.

Qajaq

[Friendly, Don't Fire!]

Never had nor heard of that one!
Good luck with finding out the problem.

I would say it IS a PROBLEM.

[243winxb]

Dirt on the brass could have scratched the die. If the cut is deep enough into the brass , the necks will split. Put some 400 grit wet emery paper of the correct size wood dowel and polish the neck area of the die.

[ranger335v]

243winxb has the correction.

But, it's unlikely the case hardened die surface is scratched, much more likley it has brass galling on the die walls. When we force soft brass across hard steel, dry, the soft brass tends to deposit itself on the steel in microscope bits. That's galling. The bits grow as we continue to do it until the bits can score the cases as you describe.

Using an electric drill to spin a split dowel snugly wrapped with 400 grit paper does a good job of removing the brass bits with little, or no, effect on the steel.

Afterwards, make sure you properly lube your cases or galling will recur.

[qajaq59]

Dirt on the brass could have scratched the die. If the cut is deep enough into the brass , the necks will split. Put some 400 grit wet emery paper of the correct size wood dowel and polish the neck area of the die. The scratches are too perfect to be caused by random dirt. They are perfectly aligned, about 20 thousands apart, and go all the way around the case. I have plenty of dies, but I've never seen anything like this. I think something wasn't finished in the manufacture.

I may try to clean them up, or I may just dump them and get a set from Lyman. But I want to see what Lee has to say first. I've only used them twice and the ones that split were the first loading. I just wish I had noticed it before I loaded them.

[Remo-99]

What type of die qajaq59?
What your describing sounds to me like a collet die. Which wouldn't give vertical scratches from sizing, but more like vertical impressions on the case neck, at regular spacings.

[qajaq59]

What your describing sounds to me like a collet die. Which wouldn't give vertical scratches from sizing, but more like vertical impressions on the case neck, at regular spacings.
Remo, you just perfectly described what it looks like. And the cracks followed those lines perfectly on both sides.
I thought I had ordered plain old fashioned dies. What did I order, and what is the reason for the impressions?
By the way, I did anneal the cases this time before I resized them hoping to avoid any more cracks.

[hiker44]

Just curious to know how many times those cases have been loaded and fired. I have a whole bag of .38SP brass that I have about 8 loads on and am watching them carefully.

[qajaq59]

The ones that split were the 3rd loading. And weren't loaded all that hot. But I have 30-30s and K31 cases that have lasted well over a dozen loads and the k31 dies are Lee's also.
It's not a big deal as the dies were fairly cheap. But if I screwed up ordering them it's better that I find out before I do it again.

Not knowing is ignorance. Not knowing, and being too proud to ask, is stupidity!

[EShell]

243winxb has the correction.

But, it's unlikely the case hardened die surface is scratched, much more likley it has brass galling on the die walls. When we force soft brass across hard steel, dry, the soft brass tends to deposit itself on the steel in microscope bits. That's galling. The bits grow as we continue to do it until the bits can score the cases as you describe.

Using an electric drill to spin a split dowel snugly wrapped with 400 grit paper does a good job of removing the brass bits with little, or no, effect on the steel.

Afterwards, make sure you properly lube your cases or galling will recur.
I agree 100% and have seen this problem, and used this fix, several times myself.

Softer brass will sometimes adhere to the die's neck/shoulder junction area, and as more cases are sized, more material collects, and it then finally becomes visible in the form of case neck scratches.

[Remo-99]

If a collet die is appyling more pressure than is nessisary for sizing, there is a possibility to weaken a case mouth, along the edges where the collet fingers impress upon the brass, by over working it.
The remedy is to screw the die down further, so the press isn't allowed to go over centre when sizing and to give the operator 'a feel' for the sizing operation.
That's only relivant, if yours is a collet die, though. Collet dies have at their base, a sleeve/collar that pushes into the die body with a case, when sizing.

[qajaq59]

Collet dies have at their base, a sleeve/collar that pushes into the die body with a case, when sizing. Nope, no sleeve. The die has stamped on it, Lee .308 H5. But your description of the lines sure sounds like what my cases looks like.
Oh well, I'll see what LEE has to say and if I have to, I'll just replace it. At least now I know what a Collet dies is supposed to look like, so it isn't a total loss.

[Friendly, Don't Fire!]

Could it be a stretching problem from a gun with excessive headspace?