Bevelling of the skull is seen in the following:

In the skull, the wound of entrance shows a punched-in (clean) hole in the outer table. The inner table is unsuppoed and a cone-shaped piece of bone is detached forming a crater that is larger than the hole on the outer table, and shows bevelling (sloping surface). Ref: The Essentials of Forensic Medicine and Toxicology by Narayan Reddy, 27th edition, Page 197.