A firearm compensator assembly includes a compensator base that may be mounted to a barrel of a firearm, the base having a contact surface. A cylindrical-shaped compensator body has a bore, an axis, a sidewall, a contact surface, an outer surface and at least one gas discharge port extending through the sidewall between the bore and the outer surface. A spring exerts a biasing force urging the body contact surface into engagement with the base contact surface whereby the body is locked to the base. The gas discharge port is rotatable around the axis by urging the body contact surface away from the base contact surface against the biasing force of the spring.