Winchester Repeating Arms SX4, Semi-automatic, 12Ga 3, 28 Barrel, Black Finish, Synthetic Stock, 3 Choke Tubes, 4Rd, Bead Sight 511205392 The autoloading shotgun that's built 4 speed. Winchester Super X(R) Autoloading shotguns have a worldwide reputation for speed, reliability and handling. The new Super X4 is lighter, faster cycling, smoother swinging and more ergonomic than ever before.