Compare two .22 caliber bullets. A. A .22 long-rifle round (left) and an M16 round (right). B,C. Wound profiles in ballistic gelatin of the same .22 long-rifle (B) and .224 caliber M-193 round of the M16A1 rifle (C). [Full metal case (FMC) is a synonym for full metal jacket, the type of bullet used in the military.] This figure shows that caliber (bullet diameter in decimals of an inch or in millimeters) is only one indicator of wounding potential and not a very good one. Because of much higher velocity [3094 ft/s (943 m/s), as opposed to 1122 ft/s (342 m/s) for the .22 long-rifle bullet], because it fragments in tissue, and because of greater bullet mass, the M16 bullet has the potential to cause a much more severe wound if the anatomic part struck is sufficiently thick. Note that in the gelatin block, both the permanent cavity and the temporary cavity caused by the M16 bullet are much larger than those of the .22 long-rifle bullet. As is usual for a nondeforming bullet, the temporary and permanent cavities caused by the .22 long-rifle bullet are largest when the bullet is at 90 degrees of yaw.
Sat, 2011-11-26 17:53