It may have been the first service pistol cartridge created after the current FBI ammunition testing standard was devised.
.40 S&W terminal ballistics are generally very good since it's a relatively powerful cartridge and most likely uses projectiles developed around the "FBI Protocol".
Are there currently any countries that allow civilians to own .40 S&W guns and ammo but totally prohibit 9x19mm?
https://en.wikipedia.org/wiki/Overvi...laws_by_nation