dorm cannon
Projectile weapon usually made from about six 12-ounce soda pop or beer cans with the all the tops and bottoms cut out except for one, which is placed at the bottom end, and held together by duct tape. Device is filled at one end with some type of explosive gas such as butane from a disposable lighter. An object such as a ball, a wadded up sock, or a potato or other vegetable is then loaded into the open end, and the gas is ignited by a lighter or lit cigarette. Makes a loud noise and, if properly made, can be used to shoot the projectile down a dormitory hallway or out a window. Not recommended for quiet floors. Generally frowned upon by Resident Advisors, college administrators, and university police.
Dude, don't come out in the hallway. Jimmy is in the stairs and is going to set of his dorm cannon.