I heard the following story told about R. L. Moore.
It seems he was teaching a class in which several of the students were obnoxious and unruly. So one day he walked into the lecture hall, opened his briefcase, took out a pistol, set it on the table in front of him, and then began to lecture as usual. He had no further trouble with the rowdy students.
I have no particular reason to believe this is true, but it makes a good story. I think I have seen other references to firearms in the math department at the University of Texas, though.