Recognizing that unique mirror image modeling of deformable bullets occurs at the impacting surface led the authors to find a rapid technique for matching reconstructed bony defects with the bullet's impacting surfaces. The bullet impact site was reconstructed by excising the surrounding bone and realigning the bony fragments. This and the bullet's impacting surface were photographed at the same magnification in the normal plane using an operating microscope. Matching was done by comparing photographic enlargements. It was determined that when bone is penetrated by a bullet, the bullet's impacting surface is often uniquely modeled by the fractured bone. Reconstructing bone with simple superimposition of the bullet's contour lines allows matching of a particular bullet to its specific bone defect. 11 references and 2 figures (Author abstract modified)