Model parts with this special rule must make a Special Close Combat Attack at their own Initiative against a single enemy unit in base contact. This attack deals a number of hits equal to the value stated within brackets (X). These attacks automatically hit and have a Strength equal to the model's own Strength. Grinding Attacks never benefit from any equipment or special rule the model may have (since they are Special Attacks). If a model has both Grinding Attacks and Impact Hits, it may only use one of these rules in the same Round of Combat (you may choose which). When several model parts in the same unit have this special rule, and when X is a random number (for example Grinding Attacks(2D3)), roll for the number of hits separately.