Factual error: At one point in the film, Morgan calls out "Riflemen, to me!". The film is set in the late 17th century. Whilst rifling had been invented prior to this date, it was still rarely used except on the most expensive weapons, and even then mostly used by specialists. It is highly unlikely that all, if any, of the pirates would have been armed with them, especially in the close quarter fighting they would have been expecting. The pirates would be more likely to be armed with the more common smooth bored muskets of the period, so "Musketmen, to me!" would be much more likely to be correct.