The following weapons were used in the anime series Afro Samurai:
Colt Single Action Army
Justice uses two 7.5" barreled cavalry model Colt Single Action Army as his main weapons. He used it to kill Afro's father. At the last battle, he tried to shot Afro, but he beheaded him.
One mercenary uses a Tanegashima to shot Afro.
After killing Soshun, Afro gets affected by a poison arrow and loses his balance just to be a sitting target for brother 6 to pull out an RPG-7 from a back pack which gives Ninja a really good surprised reaction.