Abstract: A motorized case trimmer is disclosed having a lever operated case holder and a motor driven trimming blade. The motor and blade are slidably mounted upon rails for quick and easy movement to provide sufficient clearance for loading a case into the case holder. A motor handle further simplifies the movement of the blade and motor whereby a simple one-step motion of the handle moves the blade and motor and locks them into a retracted position. Releasing the motor handle, permits the motor and blade to slide freely along the rails under urging by a pair of springs. The components of the case trimmer are mounted upon an elongate platform that permits adjustability of the position of the components for accommodating various size cases and for adjusting the cutting force of the blade against the cartridge case.