An automatic fire protection sprinkler comprising: a sprinkler body having an axially extending passageway with an outlet through which a fire suppressant fluid flows; a deflector carrier axially moveable relative to the body between a first position distal of the outlet and a second position distal of the first position, the deflector carrier having a central section and a pair of wings extending radially outwardly from the central section in opposite directions and each wing including radially extending leading edges facing the outlet and the wings taper as they extend axially toward the outlet and form the leading edges and each wing including a pair of end sections distal of the pair of wings that together define a pair of mounting locations; a pair of guide pins reciprocally coupled to the sprinkler body on opposite sides of the outlet for movement between a first retracted position and a second extended position and having axially opposite first and second ends (108,110), the pair of guide pins coupled to the deflector carrier at the pair of mounting locations, the pair of guide pins moveably coupling the deflector carrier to the sprinkler body between the first retracted position and the second extended position; and a deflector attached to the deflector carrier and moving with the deflector carrier between the first and second positions, the deflector distributing fire suppressant fluid thereon into a flow distribution pattern, characterized in that the pair of leading edges is axially upstream of the pair of end sections and is closer in an axial direction of the axially extending passageway to the outlet than the pair of end sections in both of the first and second positions and that each wing has a transitional surface that curves as it extends from the leading edge to a planar surface of the end section facing the outlet. a sprinkler body having an axially extending passageway with an outlet through which a fire suppressant fluid flows; a deflector carrier axially moveable relative to the body between a first position distal of the outlet and a second position distal of the first position, the deflector carrier having a central section and a pair of wings extending radially outwardly from the central section in opposite directions and each wing including radially extending leading edges facing the outlet and the wings taper as they extend axially toward the outlet and form the leading edges and each wing including a pair of end sections distal of the pair of wings that together define a pair of mounting locations; a pair of guide pins reciprocally coupled to the sprinkler body on opposite sides of the outlet for movement between a first retracted position and a second extended position and having axially opposite first and second ends (108,110), the pair of guide pins coupled to the deflector carrier at the pair of mounting locations, the pair of guide pins moveably coupling the deflector carrier to the sprinkler body between the first retracted position and the second extended position; and a deflector attached to the deflector carrier and moving with the deflector carrier between the first and second positions, the deflector distributing fire suppressant fluid thereon into a flow distribution pattern, characterized in that the pair of leading edges is axially upstream of the pair of end sections and is closer in an axial direction of the axially extending passageway to the outlet than the pair of end sections in both of the first and second positions and that each wing has a transitional surface that curves as it extends from the leading edge to a planar surface of the end section facing the outlet.