A case activated drum powder measure includes a measure body, a powder drum, a drive assembly and an actuation assembly. The measure body includes a drum receiver, an actuation tube and a hopper. The powder drum includes a powder cavity and is retained in the drum receiver. One end of an expanding die is secured to the actuation tube and the other end is secured to a loading press. A connecting rod transmits linear motion from the actuation assembly to rotate the powder drum through the drive assembly. Gun powder fills the powder cavity through the hopper. A case is retained in a shell holder retained in a ram of the reloading press. A lever arm is pulled, which causes the ram to push the case into the expanding die. Upward movement of the case causes the gun powder in the powder cavity to fall into the case.