Experimental soft tissue wounds caused by standard military rifles.

Soft tissue wounds were caused by penetration of a bullet through both thighs in 42 pigs, fired from N48, M70, M16A1 and FAL rifles at 50 meter range. Four comparable groups of wounds, consisting mainly of injured muscle, were examined. Primary debridement was carried out 5-6 hours following wounding, multiple muscle biopsies up to 40 mm sidewise of permanent wound channel were taken for HE and histochemistry. Primary contamination was traced using marker aerobic bacteria. Bullet velocities at impact and exit were measured and transfer of energy to liver tissue calculated when feasible. The condition of the bullet after exit was precised. The surgical estimation of tissue injury, the mass of excised tissue and microsections have served to evaluate the extent of tissue injury. For 22.5 cm mean channel length the most injury was caused by the FAL, followed by M16, M70 and M48 rifles in declining order. Local effects are ascribed to bullet tumbling, break-up and energy transfer of corresponding missiles. Correlation of surgical and pathology methods is discussed.