If that’s factory loads, contact manufacturer. Are the primers popping out?
Typically for split necks you have a few things that cause it. We see this more common in reloading.
Brass is worn out from resizing too many times
Improper neck sizing
Over pressured – too hot of a load creating too much psi for the brass to handle. This is probably the most common. Using powders with incredibly fast burn rates build pressure much faster.
Very rare, but sometimes the throat to the lands in the rifle is Bored too Large allowing the brass to over expand too much. We had that in a Browning and savage in larger calibers.