For two cartridges to be so different ballistically (sp?) they could not be more similar when it comes to street effectiveness. These two are my top two choices when I need to count on a handgun to be able to put someone down and keep 'em down. The .45 has been around for over 90 years and the .357 has been around for over 65 years, and we haven't found a better man stopping handgun round yet. Take your pick, you can't go wrong. I will say that in a revolver .357 (5- J frame, 6-K frame, 7-L frame or 8-N frame rounds) beats .45 (5-L frame or 6-N frame) in capacity/size efficiency, but the .45 is more pleasant to shoot.