Split case necks - Hornady brass

[603 Country]

[biodsl]

What's the make on the barrel? What's the load recipe? Something's not right, that's for sure.

[LRRPF52]

[603 Country]

[LRRPF52]

Did you use Imperial Wax by chance?

I only had one split neck back when I first started loading for Grendel.

Once I switched to One-Shot spray-on lube, I never had it again.

I primarily reload Lapua and Hornady brass and run it through AR-15s.

[grayfox]

The neck splitting I had, couple years ago, in creed was due to not using any lube inside the necks. On 4th resize/new+ 2-3 firings, also. Like '52 says, use some spray 1-shot and that gets some lube into the inside of the neck.
The excessive work hardening of the neck area is what I would suspect. I was using rcbs lube on the outside but inside necks were bone dry. Once I made the switch and got some 1-shot on the inside neck, the splits stopped. Footnote, also a 40-yr (oops now 50!) reloading veteran, but learn something new every day!

[biodsl]

Like '52 says, use some spray 1-shot and that gets some lube into the inside of the neck.
The excessive work hardening of the neck area is what I would suspect. I was using rcbs lube on the outside but inside necks were bone dry. Once I made the switch and got some 1-shot on the inside neck, the splits stopped.

Interesting. I ever only used One Shot. I've never had a split neck.

[603 Country]

[lazyengineer]

Grendel SAAMI spec is one sloppy neck dimension.
While everyone keeps talking about primer cavity, all my brass I lose, is due to split necks.

[LRRPF52]

[Klem]

Never had a split neck or loose primer pocket in Grendel, using only Lapua.

In the larger case 6.5x47 the first sign of wear are loose primer pockets, using only Lapua. Never had a split neck in this calibre either.

Split necks for me are more common in handgun, Using all sorts of brass and multiple reloads.

[603 Country]

[NDSwede]

LRRPF52 mentioned that he has primarily seen split necks when using Lee dies. I use Lee dies to resize brass and was recently looking to upgrade to a full length bushing resizing die. While looking into that, I discovered that Lee dies size the neck down more than other dies and then the expander ball expands it back up to 2 thousands below bullet diameter. This cold works the brass more than other dies and can contribute to split necks. Something to think about, especially if the Grendel chamber neck is cut a little oversized. Your problem could be a combination of things like this which overworks the neck and causes splits. Personally, I'm planning to go to the Redding full length bushing resizing die. (~$95+15=$110) This will allow me to bump the shoulder back 2-3 K's and resize the neck 2K under bullet diameter. I think Hornady makes this kind of die also, but not for the Grendel. The Redding die is expensive, especially for a tight wad like me. I'm trying to learn the expression "buy once, cry once."

[LR1955]

603C:

What sizing die are you using?

LR-55

[603 Country]