Re: 7mm Rem Mag bullets pushing deep into the case with recoil
KDL, after sizing, measure your outside neck dia. After seating a bullet, measure it again. The Dia. should have increased by .001-.002" This is the amount of grip the brass has on the bullet. If it's under .oo1, you can do what Dan said about polishing the expander ball. Your brass may have thin neck walls measure them also should be around .015". If they are thin the size die will not work with that brass because the outside dia. would have to be smaller to get the inside dia. small enough to grip the bullet.