The rail gun has the potential of developing into an impact fusion macroparticle accelerator, and it is the most promising electrical accelerating system since its efficiency can be high, its length relatively short, and there is a considerable body of experimental work. The next step in rail gun development would be to increase the velocity by a factor of three or four using three to five gram pellets. The final goal of rail gun research and development would then be to increase the velocity by another factor of five to six to obtain impact fusion parameters