[Comparative studies of bullet entrance holes in trunk and extremity bones of predominantly spongious structure].

Abstract

The size relation between the bullet calibre and the minimum diameter of the entrance hole in extracranial bones of predominantly spongy structure was systematically investigated. Test shots (cartridges .22 lr, 7.65 mm Brown. and 9 mm Parabellum) on bone specimens covered with soft tissue (coxal end of the femoral bone, ala ossis ilii, corpus sterni) showed the following results: The entrance holes in bone produced by solid-lead projectiles of calibre .22 showed a tendency towards larger diameters compared with the bullet (deviations at the proximal femur up to about 20%); full-jacketed bullets of calibre 7.65 mm and 9 mm mostly produced entrance holes which were smaller than the cross-section of the projectile (deviations at the sternum and os ilium up to about 12%). For perpendicular hits it was possible within one test-firing region to assign the minimum diameters of entry to one of the three calibres without any overlapping in the borderline area. The measurement results classified according to calibre and area of entry are indicated in diagrams.