*** Originally posted by claymore ***
Probably the biggest difference is the material they are made of, the old ones are plastic and look like plastic very shiny very light the newer the model the better the material, hw, shw and the guns look better. that apart the rounds themselves are different the old models dont have real size rounds and the caps normally fit externally inthe bullet nose. new ones have a real size round and the cap fits inside the round which means you dont need the chamber blocks to act as a detonater. Dont think there is any difference otherwise.
And as for metal models i think only the rounds are different