Kids in class keep saying I'm bad at math so I'm about to teach them 7.62x39.
I'm not sure I understand what you are saying. Are you referring to guns?
I'm only saying that its easy to kill people.
Joking about shooting classmates is a serious thing and not something that should be done. If someone overhears that they will be upset or you could even end up in trouble in school or with the law.