Thread: Lapua 6.5 PRC Brass - Split Necks

Whats the soloution your using in ultra sonic cleaner

Yeh iv been down this rabbit hole. I did returned my brass back to the supplier and they said it was a bad batch, however I’m not convinced. I have done annealing on the same brass with no change to brass life and I also tried adg brass. My end result was to change to a bushing die and working the necks as little a possible. End result was no more split brass. I currently still load for my rifles and continue not to anneal.

Originally Posted by dale

Yeh iv been down this rabbit hole. I did returned my brass back to the supplier and they said it was a bad batch, however I’m not convinced. I have done annealing on the same brass with no change to brass life and I also tried adg brass. My end result was to change to a bushing die and working the necks as little a possible. End result was no more split brass. I currently still load for my rifles and continue not to anneal.

Also what I did that made me help identify my problem was, measuring the new next, then a fired neck. Then full length size but without the expander ball and then re size again with the expander ball in.

I found my brass was being worked to much

Originally Posted by gqhoon

I’d be inclined to sacrifice another case by running it through the AMP and confirming the correct Aztec code and that the cases are being annealed adequately.

It would take excessive headspace and brass flow into the neck to have thickened it enough that your original Aztec setting is no longer valid, but it’s not impossible.

Have done this, and interestingly aztec came up with a lower number this time compared to when i originally tested this batch of brass, suggesting its softer now than it was from new & now requires less annealing?

Originally Posted by dale

Also what I did that made me help identify my problem was, measuring the new next, then a fired neck. Then full length size but without the expander ball and then re size again with the expander ball in.

I found my brass was being worked to much

Interesting, will take the expander ball out and so some measuring. Although i find it strange its only some cases that go bad, majority of them are perfectly fine. Same dies that i used for my last PRC too & had no issues with the last batch of lapua brass in that rifle

Given that you’ve been annealing the brass and getting this problem, perhaps try NOT annealing and try that on a few cases. Remove one variable at a time and you will find the problem.

I would think it's just a bad batch. I do my brass on the amp every cycle and I've never once seen a crack on a single neck. Gotta be the quality of the brass surely

I have reloaded over 600 prc cases and have never had that problem.
I anneal my brass before resizing with bushing dies but dont use a mandel or expander ball, the projectile when seating is the mandrel.
I also decap primers first with a decaping die.

It could be possible you are over working the necks if you are using a bushing die and expander ball, just my 2c worth.

I think it's is probably a bad batch of brass.

To remove the 'over working' of the brass variable try annealing, bushing sizing die without mandrel, anneal again then mandrel the necks. If they still split then it isn't over working of the brass.

I'll be shooting some new peterson brass in my 260rem next chance I get to see if they split like my Norma brass is currently. If it does then I know it's the rifle, load or the dies (or combination of).

Ive come to the conclusion its faulty brass. Mainly because my processes are the same with not just this brass but all the brass for all my rifles, and ive never had this before. Not to mention, most of this batch is fine, its only a few of the cases that are doing it and they are all annealed sized and loaded the same.

i finally got round to shooting my .260 with some peterson brass and some more of the norma brass that is pinhole/splitting in the neck.
Fired brass in the chamber headspace comparative measures at 1.630"

The Peterson brass went mint, no splits/ issues. 5 pieces fired 3 times with stout loads. New length of 1.622" and then fired and sized h/s of 1.627".

The Norma i found was more prone to split when sized to 1.620" (by previous owner) on the first or second firing. When i sized them at 1.625-1.627" none appeared to have split.

So i'm putting the splitting down to excessive headspace and poor brass.

Mine definitely isnt a headspace issue, ive been bumping the shoulder back a thou. Basically all of my lapua brass is wrecked now, slowly but surely the ones that were ok are now buggered. All i can put it down to is a bad batch of brass. Some of my creedmoor lapua brass has been punished pretty hard & all the necks are mint. Same loading processes.

Yeah sorry I was implying that is the reason for my Norma brass splitting.

Yours definitely seems to be bad batch brass.

I had some hornady that was splitting the same way.

Just came across this while day dreaming.

I had the same issue. Was dirt in my chamber. Got it out with a pick.

Cheers