|Drawing of a Lian Zi Chong, from 'Ji Xiao Xin Shu (《紀效新書》)'.|
When the fuse is lit, gunpowder charges will be ignited one by one, shooting lead balls out of the barrel one at a time until entire magazine is spent. Once Lian Zi Chong starts firing, there is no way to stop it. In a sense, Lian Zi Chong is basically a Roman candle in gun form.
While this weapon isn't impractical to the point of completely unusable, it is notoriously weak, inaccurate and unreliable.