So I'm curious why there are so many calibers for someone looking for a handgun for self-defense. There's .25, .32, .380, .38 Special, .357 magnum, .357 Sig, 9x18mm, 9x19mm, .40 S&W, .41 magnum, .45 ACP, and 10mm just to name a few. For semi-automatic rifles that people use for HD or protection...