Looks like you have two shoulders....
I shot a 7mm mag for years stoked full tilt....neck sized only without any issues. The primer pockets will be the first thing to go.
After about 3 loadings I just pitched the brass.
The belted magnums head space on the belt....why the need to bump the shoulder ?
You sort of missed the boat, here. Headspacing on the belt can cause excessive case stretch through the body, leading to case-head separation, etc. Creating a false shoulder allows the case to headspace on the false shoulder and fireform, so that it headspaces on the shoulder-proper on subsequent firings.
The bottom line is that brass lasts 15+ firings, if taken care of.
