Particle shape affects the resistance to shear of a granular material and its flow characteristics. Rocks in a Semi-Autogenous Grinding (SAG) mill range in shape from quite rounded to quite angular depending on how long they have been in the mill and whether they have undergone body breakage recently due to collisions within the mill. However, almost all Discrete Element Method (DEM) modelling of SAG mills, particularly at industrial scale, has used spherical representations for the rocks. Here we explore the consequences for including a realistic range of particle shapes for the rock particles on the charge structure, power draw and energy utilization over a representative range of operating conditions.