Two minor Blue Jay variants were studied but not adopted. The Blue Jay Mk.2 included the more powerful Magpie II motor and a PbTe seeker which offered better detection capabilities. Blue Jay Mk.3 had an increased wingspan and reduced performance motor. The derated motor was intended to limit acceleration when launched from supersonic rocket-powered interceptors such as the Saunders-Roe SR.177 and Avro 720, where the additional speed imparted by the Magpie II would have given it a maximum speed so high it would suffer from adverse aerodynamic heating.