Implementations described and claimed herein provide systems and methods for increasing accuracy of firing perforating charges in an oil well casing. In one implementation, a body of an orientation device has a first portion and a second portion. An opening extends through a center of the body from a first lateral surface to a second lateral surface, and the opening is configured to receive a perforating gun string. An outer perimeter surface extends about the center of the body from the first lateral surface to the second lateral surface. The outer perimeter surface has a first shape associated with the first portion and a second shape associated with the second portion. The second shape forms a base portion configured to maintain the perforating gun string in an orientation by preventing rotation of the perforating gun string. The orientation corresponds to a predetermined perforating charge direction of the perforating gun string.