Hodgdon Powder has generated load data which recommends using Win. Large Rifle Primers.
Cor-bon has also tested and recommends CCI 250 primers (Magnum Large Rifle). Our new cases will have an "R" after the "Mag" on head stamp to signify rifle pocket. If you have previously purchased 500 cases without "R" on head stamp and wish to modify, you can use a large rifle pocket uniformer to deepen primer pocket to accept large rifle primers by deepening pocket approximately .006". This will not affect integrity of case.