A bullet may ricochet off many surfaces, including water.
The angle of incidence is the angle of the bullet path relative to a surface. The critical angle of incidence defines the maximum angle of incidence at which the bullet will ricochet. A bullet striking with an incident angle greater than the critical angle will usually penetrate the surface, break up or flatten, depending on the nature of the surface.
The critical angle is affected by the nature of the surface and the velocity of the bullet.
Factors about the bullet which influence how well it ricochets:
(1) A bullet with a rounded nose is more likely to ricochet than one with a square nose.
(2) A fully jacketed bullet is more likely to come off intact, while a partially jacketed bullet may break up. These fragments may embed in the victim.
A bullet that strikes a hard surface may be flattened on that side. This flattening may be mimicked by a soft non-ricocheting bullet that strikes a bone.
After a bullet ricochets it usually has an unpredictable trajectory and often tumbles. A bullet wound made by the bullet will often have ragged and irregular edges.
A ricochet bullet may be imprinted with markings made by a surface through which it passed.
If a person who is hit by a ricochet bullet is close to the richochet surface, then bits of the surface which have been knocked off may pepper the patient.
