Misfire
From PyroGuide
Misfire - shell does not fire. A misfired shell in a mortar should not be removed for at least one minute due the possible presence of live spark inside the shell fuse. It would be best to then dump the shell out behind something solid or into a steel bucket preferably with some water in the bottom.
[edit] References
- Queensland Government : Queensland Code of Practice, Control of Outdoor Fireworks Displays - First Edition - 1 December 2003