Flintlock hand mortars were use for signaling, launching fireworks, and hurling grenades.
They would be operated by two men. One who would insert a lit grenade then duck. The first man ducking would signal to the second man, the shooter, the mortar was ready to fire.
In the event of the mortar not firing when a lit grenade was inserted the operator would throw the device and reel it in by an attached strap.
Ian’s Video: [5:48] https://youtu.be/kf9URQ7X0YA?si=
InRangeTV Video: [7:01] https://youtu.be/mAzdYxa6kHA?si=
Is there even anything to reel back at that point?
The idea is you throw as soon as pulling the trigger doesn’t set off the charge , then you yank it back so the grenade in the tube falls out, and you just duck and hope for the best.
So you better have a long enough fuse on that grenade/firework to give you OH SHIT time.