A gas assisted spray nozzle assembly comprising: a nozzle body in the form of a cylindrical tubular member which extends substantially the lengh of the spray nozzle assembly, said nozzle body having a mixing zone and a barrel extension zone downstream of the mixing zone longer in axial length than the mixing zone; a liquid inlet supported by said nozzle body through which a liquid stream is directed into said mixing zone; an impingement pin supported by said tubular member and extending into said mixing zone having an outer impingement surface in substantial alignment with the liquid inlet against which a liquid stream directed into said mixing zone from said liquid inlet impinges; a pressurized gas inlet mounted in an upstream end of said nozzle body through which a pressurized gas stream is directed into said mixing zone along a central axis of said mixing zone for atomizing liquid impinging upon said impingement surface; and a spray tip mounted at a downstream end of said tubular member having a discharge orifice through which said atomized liquid is discharged in a predetermined spray pattern characterized by said impingement surface of said impingement pin being disposed in radially offset relation to the central axis of the mixing zone on a side opposite the liquid inlet a distance of between 1/8 and 1/3 of the radius of said mixing zone, and said impingement surface being formed with an inwardly directed recess for receiving the liquid stream introduced into said mixing zone from said liquid inlet and directing the liquid away from the impingement surface and toward the central axis of said mixing zone for intermixing with the pressurized gas stream introduced into said mixing zone from said gas inlet for enhanced break down and atomization of the liquid for direction to and through said barrel extension zone and spray tip. a nozzle body in the form of a cylindrical tubular member which extends substantially the lengh of the spray nozzle assembly, said nozzle body having a mixing zone and a barrel extension zone downstream of the mixing zone longer in axial length than the mixing zone; a liquid inlet supported by said nozzle body through which a liquid stream is directed into said mixing zone; an impingement pin supported by said tubular member and extending into said mixing zone having an outer impingement surface in substantial alignment with the liquid inlet against which a liquid stream directed into said mixing zone from said liquid inlet impinges; a pressurized gas inlet mounted in an upstream end of said nozzle body through which a pressurized gas stream is directed into said mixing zone along a central axis of said mixing zone for atomizing liquid impinging upon said impingement surface; and a spray tip mounted at a downstream end of said tubular member having a discharge orifice through which said atomized liquid is discharged in a predetermined spray pattern characterized by said impingement surface of said impingement pin being disposed in radially offset relation to the central axis of the mixing zone on a side opposite the liquid inlet a distance of between 1/8 and 1/3 of the radius of said mixing zone, and said impingement surface being formed with an inwardly directed recess for receiving the liquid stream introduced into said mixing zone from said liquid inlet and directing the liquid away from the impingement surface and toward the central axis of said mixing zone for intermixing with the pressurized gas stream introduced into said mixing zone from said gas inlet for enhanced break down and atomization of the liquid for direction to and through said barrel extension zone and spray tip.