I don't know about the .350 Mag, but I owned one briefly in .308 in the early 80s. The only way to describe the muzzle blast is "horrendous."
Then, there is always this:
Safety Modification Program - Shotgun Safety Modification - Rifle Safety Modification
My brother shot a hole through three walls of the house he was renting in the early seventies. They were bad about "going off" when you closed the bolt on a live round.