Hornady Brass

[grayfox]

Could be the neck splitting comes from over-cold working during sizing. Do you spray some one shot especially into the inner neck/case mouth area while spraying the cases... I had some splitting a few yrs back, switched to the one shot ensuring the case mouth got some too and haven't seen any splitting since. I even monitor the new cases being sized to make sure not to add too much work hardening from dry case mouths.
One idea anyway.