Dude this is an UZI...
Submachinegun...
WHY IS THAT WOOD HANDLE OVER THERE?!
Since I can tell you learned about guns from Call of Duty...
Submachine guns usually have stocks. There's no magical crosshair floating in front of you, so using the iron sights is required. When using iron sights, placing a stock againt your shoulder improves your recoil compensation.
Uzi's don't have much recoil, but if you just held it in front of you and sprayed, you have enough to make you completely miss what you're shooting at.