Here are some of the reasons people cite to justify carrying a tiny pistol:
“I can’t conceal a large pistol.” I’m of average build and have no problem concealing a pistol such as a Glock 19 in an inside-the-waistband holster during the summer when wearing cargo shorts and a T-shirt. During other times of the year, a sweater, jacket or coat easily conceals even larger guns.
“A larger gun is too heavy.” Usually, the difference in weight is not substantial and can be offset by the proper holster and a good belt.
“Advances in bullet design make the small calibers more effective than they used to be.” That might be so, but bullet design has seen advances in the morepowerful chamberings, too.
Much of bullet design today is concerned with overpenetration. But a bullet might still have to pass through heavy clothing and bone to reach the vitals, so I would contend that underpenetration is just as big an issue. I put more faith in the documented, real-world results of the .357 and .45 than I do in the artificial lab results of some company’s high-tech, light-for-caliber .380.
“Bullet placement is still the most important thing.” Sure, it is. I might be able to shoot a .380 more accurately and faster under stress than a 9mm or a .45, but that comparison has to be made with guns of the same size. Compare a tiny, superlight .380 to a midsized 9mm or .45, and I’d bet on the larger gun every time.