This is a S&W 4043, in 40 Caliber. S&W Models 4006 / 4043 /4046 were the first guns to be specifically engineered to fire the .40 S&W Round. She's got an alloy frame, but an all stainless steel slide, DA Only, with a 4 inch barrel. She weighs in at 2.04 lbs. She's a full size combat gun and uses...