Originally Posted by
DocGKR
TISSUE SIMULANTS:
Currently, a variety of equally important methodologies are used for terminal performance testing, including actual shooting incident reconstruction, forensic evidence analysis, and post-mortem data and/or surgical findings; properly conducted ethical animal test results; and laboratory testing--this includes the use of tissue simulants proven to have correlation with living tissue. All of these areas provide important information. As noted earlier, the tissue simulant that has proven to most closely correlate with living muscle tissue is Type 250A ordnance gelatin at 4 deg C.
Other simulants fail to provide accurate replication of various facets of projectile terminal performance that occur in shots to living human tissue. Cadaver tissue lacks elasticity, tends to be disrupted by pressures that would simply push living tissue aside, and demonstrates exaggerated projectile effects leading to far more extensive damage than that produced in living tissue. Animal testing in cattle uses living tissue, but normal anatomic and physiological differences between individual animals leads to substantial differences in terminal effects; in addition, there are substantial differences in animal anatomy compared to human, animal testing is quite expensive and time consuming, and accurate data collection and comparison is difficult. Water is a good simulant to show maximum projectile upset, but penetration is 1.6-2 times deeper than in tissue and stretch effects are not visible. Inelastic simulants such as clay, duxseal, and soap can provide good estimates of penetration depth and bullet upset, but exaggerate stretch effects from the temporary cavity. Perma-gel and other synthetic polymer simulants can provide a reasonable result for bullet penetration and expansion, but under-represent bullet yaw, fragmentation, and stretch effects. Computer modeling may one day provide the best opportunity to study projectile effects outside the human body, however to date, the current models are overly-simplistic, use too many excessively averaged assumptions of anatomic and physiological factors, and fail to fully and accurately represent the complex dynamics of the interaction between living tissue and penetrating projectiles.