because it's VERY difficult indeed. an average of .20 second splits, full charge ammo, N frame 357 isn't something Miculek would bet on keeping in 10" at 10 ft,and he's been PAID to work at DA pistol stuff, for MANY years, by Clark Custom Guns, and has had his ammo and guns provided by Smith and Wesson. So you will be MANY years achieving it, if you indeed EVER do so.