I used to own several .40 S&W handguns, but have since lost all interest in the cartridge. Here is why.
-Every .40 S&W gun I've owned or tried was less accurate than its 9x19 or .357 Sig counterpart.
-From a full-sized, or even mid-sized gun, I can get either a bigger bullet (.45 ACP) or a faster bullet (10mm Auto).
-From a small gun, .40 S&W is just plain unpleasant to shoot. For truly wee guns I'd rather shoot 9x19.
-.40 S&W doesn't really have much of a power advantage over 9x19. And sometimes NONE at all. Winchester RA9TA is more powerful than most .40 S&W ammunition, for instance. So that only leaves you a 0.045" increase in diameter. Big whoop. And 9x19 ammo is still cheaper.