The dynamics of a rigid body sliding on a frictional contact can have multiple solutions as well as sudden contact-mode transitions. This paper is concerned with dynamic jamming, an event where a sliding rigid body suddenly jamms and experiences an impact-like transition into free flying mode. Using a simple experiment that mimics a sliding rigid-body situation, dynamic jamming is recorded for the first time. The phenomenon occurs almost at the theoretical position-and-velocity prediction, indicating that this type of jamming is not a mere artifact of the rigid-body modeling paradigm. A new interpretation of dynamic jamming is offered in terms of the body's instantaneous acceleration center. Once this center reaches a graphically determinable jamming line, the body ceases its sliding mode and experiences a dynamic jamming event. Based on this insight, some ways to prevent dynamic jamming are discussed.