Thread: Split shoulders

Originally Posted by Marty Henry

Ook please pass me that banana

Please read and understand Recovery Annealing https://www.ampannealing.com/about-brass-hardness/ .
Metallurgists discuss annealing as involving recovery, recrystallization and grain growth stages. In the recovery stage hardness remains relatively constant as some of the original properties of the brass recover,

Most likely your previous reloader has just reloaded the cases to their max. times and age has done the rest with storage being a factor .