You have difficulty placing a double charge of powder in a shotshell, not able to crimp the shell closed.
That is a classic obstruction caused blow-up, perhaps caused by the wad of the previous shell staying in the bore, low powder or no powder, the primer alone will propel the wad up the bore 12" or so.
Lucky no-one was seriously hurt
That is a classic obstruction caused blow-up, perhaps caused by the wad of the previous shell staying in the bore, low powder or no powder, the primer alone will propel the wad up the bore 12" or so.
Lucky no-one was seriously hurt