Algodoo

It`s a reloadable shotgun.
manual reload (entirely drag tool), pull the barrell down, insert new shell, close the gun (it`s a bit tricky, but when u get used to it its pretty simple)
press numpad 0 to fire.

simple mechanism, but effective

NOTE: Shells are a bit unstable, i`ll try to improve them in the future.
Not all pellets get out most of the times.