Split neck with factory ammo?

[stxhunter]

I was inspecting my brass before removing their primers and noticed one of the necks was split. This is factory nosler 260 ammo.

I saw no other pressure signs such as cratered primer, ejector swipe etc.

I measured the thickness of the brass on the neck on this lot of ammo and found them to be .013, previous nosler brass measure .015 and Lapua measures 0.016. Not sure if it was the thickness of the brass or just a high charge??

[TxNurse]

Maybe they outsourced to Winchester.

[Drycreek3189]

Strange things can happen even with factory ammo. I once had a 7-08 round make a " softer " report and the bullet hit about a foot low. It turned a high shoulder shot into a shot that clipped the brisket on a nice buck. I hope he lived over it.

[Leverhunter]

I have had it happen a couple times on factory ammo. Maybe thin or brittle brass, didn't notice anything else different.

[treestand]

Could be excessive headspace. That will definitely show up as split case necks.

[softpoint]

Just a bad piece of brass is all. No need to be too concerned unless a lot of your brass splits. excessive pressure will usually show up in other ways before split necks become a normal occurrence. Annealing your brass will prevent neck splitting even if you have a slightly oversize chamber. Longitudinal splits such as that are not an excessive headspace problem, normally. If the separations were circumferential around the neck to shoulder junction, you might have a problem.