External Beveling
Definition
The cone-shaped defect geometry at an exit gunshot wound in bone: the inner table diameter (entry face of the defect) is smaller than the outer table diameter (exit face), because tensile failure on the outer table produces a wider fracture zone.
- Location
- Exit gunshot wound in bone
- Geometry
- Cone shape, wider on the outer table
- Mechanism
- Tensile failure of the outer table
- Contrasted with
- Internal beveling at entrance wounds
Common questions
Why does the outer table fracture wider than the inner table at an exit wound?+
Bone is weaker under tension than compression. As the projectile pushes through, the inner table fails first under compression near the bullet's path, while the outer table fails under tension as it bulges outward, producing a wider fracture zone.
Can beveling direction alone determine bullet trajectory through a skull with multiple wounds?+
It identifies which side is entrance and which is exit for each defect, which combined with defect locations lets a pathologist reconstruct the general trajectory, though beveling alone does not give the shooter's exact position without additional scene information.
Related terms
- Bearing Surface Diameter
- The diameter of the projectile face in contact with the bone surface at the moment of impact; smaller than the resulting defect...
- Contact Wound
- A firearm wound produced when the muzzle is pressed against or within a few centimetres of the target surface. Characterised by a...
- GSR (Gunshot Residue)
- Primer-combustion products (classically lead-barium-antimony compounds, now also non-lead formulations) deposited on the bone surface at close or contact range; detected by SEM-EDX...
- Internal Beveling
- The cone-shaped defect geometry at an entrance gunshot wound in bone: the outer table diameter (entry face) is smaller than the inner...
- Keyhole Defect
- An asymmetric gunshot defect produced by a projectile striking bone at a shallow angle; one end shows a conventional beveled entry geometry...
- Puppe's Rule
- The 1994 formalisation of the principle that radial fractures from a subsequent gunshot terminate at fracture lines already produced by a prior...
- Secondary Projectile
- A bone fragment or other material driven at high velocity through adjacent tissue by the primary projectile's passage through bone; produces irregular,...
- Stellate Fracture
- A set of radial cracks extending outward from the main gunshot defect, produced by compressed propellant gas pressure radiating under the scalp...
- Trajectory Reconstruction
- The forensic procedure that integrates the osteological bevel direction, angle-of-impact estimate, and the physical scene evidence to reconstruct the relative positions of...