put a pistol to (one's) head
To force or pressure someone to do something. Kristina, you don't have to move if you don't want to—no one's putting a pistol to your head.
hold/put a ˈgun to somebody’s head
force somebody to do something that they do not want to do by making threats: He had to sack a hundred workers last week. He didn’t want to, but the bank was holding a gun to his head.