Yes, this gun will be an N frame. The 10mm was the round the FBI used back in the day, however due to recoil they loaded the round down quite a bit, this was called the "FBI load". S&W caught wind of this and decieded to just trim the case down and have a smaller round with just as much power as the "FBI loads". Some people refer to the .40 S&W as the "Short and weak". the .40 S&W is just a bit shorter than the 10MM, kinda like a .38spl compared to a .357 mag.
