A gas turbine includes a rotor having a rotor groove and a rotor bore extending through the rotor, the rotor bore having a diffuser-shaped rotor bore exit. A blade is attached to the rotor and includes a blade tip having at least one dust hole. An airfoil has a leading edge and a trailing edge extending along a longitudinal axis of the blade between a lower end of the airfoil and the blade tip. A blade root is disposed at the lower end of the airfoil and is configured to be removably disposed in the rotor groove. The blade root includes a blade inlet having a cross sectional area that exceeds a cross sectional area of the rotor bore in at least one direction. A hollow blade core is disposed in the airfoil and extends along the longitudinal axis of the blade between the blade root and the blade tip.