When might a shotgun experience a stovepipe malfunction?

A shotgun may experience a stovepipe malfunction when the chamber is dirty because a dirty chamber can impede the smooth extraction of the spent shell casing. During the cycling of the action, if the casing does not properly eject due to grime or buildup, it may become stuck, causing the next round to jam against it rather than feeding smoothly into the chamber. This results in the spent shell casing being left partially extracted, resembling a stovepipe, which is where the term comes from.

Issues like having too high ammunition, a broken firing pin, or an excessively oily slide can lead to different types of malfunctions but are not directly related to the stovepipe malfunction. High ammunition can affect pressure and cycling but doesn't specifically cause the casing to get stuck in a manner typical of stovepiping. A broken firing pin affects the ignition of the round, and while lubrication is important for operation, too much oil can lead to failures in cycling, rather than the specific stuck casing scenario associated with a dirty chamber.