The first handgun I ever bought was a Sigma 40S&W, the day a I bought it I went to shoot a box of rounds just to have the firing pin break. S&W said it happens all the time on these and fixed it for me. I will never have another Sigma but I love older S&W. My dad bought an old S&W 22 revolver this morning that is perfect not a scratch, and looks to have never been fired. It just reminded me of how much I love S&W, especially older ones. This S&W is a piece of art in my opinion, they just don't make them like this anymore.
I sold my Sigma off after it got fixed and I bought a 9mm Glock Compact. Until recently I couldn't find reasonably priced 9mm ammo, I could have bought all the 40 I wanted at reasonable prices. I enjoy the 9mm but I wished ammo was cheap and easily found like it used to be. If my 40 Sigma would have worked I would still have it today.