IMO, primer pocket growth is tied to support the chamber/action provides.
'Hot loads' are relative to this and other support areas.
My reasoning; with sloppy chamber clearances around the web area, your cases will expand more in the web area. It's more case body expansion, but this provides a place for web brass under pressure to go(squish out).
They will shortly expand to yielding, which is not easy to undo if possible at all, given that we don't size webs. Even small base body sizing does not restore webs, but moves brass above webs, and there is no reason the movement would just happen to go back towards and restoring webs. So pockets only get looser(never tighter).
The breach end is also turned down & threaded, there is less barrel steel around the chamber, and threading to expand into. No doubt the chamber expands more & more nearing the breach than toward the shank.
And then there is little actual support for webs with rimless cases and typical bolt actions anyway.
There is a big crowd here that would preach otherwise, but consider actions to provide more chamber support for greater case life with higher pressure loads:
- Put as much barrel steel as practical around the chamber(magnum diameter action)
- Use tight clearances around the web area(with respect to new/unyielded case dimension)
- Where a choice, choose tight threading, finer thread pitch & shallower better threading for your action
- You don't want the first few threads carrying the load, and unloading on firing, so load all threading, and pretension away from the boltface(e.g. Savage barrel nut, remage)
Yielding can be managed to a stopping point that is not an end of case service.
It applies to all portions of our cases, with angle added as a factor for shoulders.
In other words, you can plan for longer brass life, with hot loads, but the plan would include a fitted chamber w/resp to NEW brass plus any improvements.
This is analogous with building of racing engines. It's not intuitive to accept, but racing engines employ very tight clearances, with very low tolerances.
The shade-tree days of sloppy clearances and accepted engine failure rates went out with Smokey Yunick's experimental NASCAR testing. Today, our manufactured engines are higher precision and last a lot longer because of his tested results, which were opposite of what everyone was doing back in the day.