I started shooting a new to me rifle and after two sessions (18 rounds) it blew the primer out of the casing. The rifle was cleaned between sessions. Shooting federal off the shelf rounds through Kimber 8400 300WSM. There are nick marks on the rim of cartridge as well as the blown primer. A friend who knows more about guns than I said it sounds like problems with either pressure or head space.
Someone recommended M&M gunsmith in Butte. Anyone be able to share experience with them or recommend another gunsmith to look at this problem?