Im not sure what your talking about? Taking a 13xx or 22xx and making it into a PB?!
The shot pistol uses a Crosman 1100 shotshell in a smoothbore barrel. Shot or a .375 lead ball can be loaded in the shell casing. The general pattern is a bolt-operated telescoping barrel. The shotshell is used as a breech seal and is used with both shot and ball; as many as 25 shots at a velocity of 280-310 f.p.s.