Developing and testing improved media in which the effects of bullet wounds could be simulated. This led to the widespread acceptance of 10% ballistic gelatin for evaluating penetration and expansion of projectiles.
Establishing effects of projectile design and shape on wounding.
He hypothesized that wound depth was much more important than previously thought, and recommended ammunition that could send a bullet at least twelve inches into his ballistic gelatin.
He was the first researcher to demonstrate that fragmentation was the most effective means of inflicting wounds in a modern military rifle round. He asserted that yawing and cavitation do not typically cause severe tissue trauma. Or, that the "permanent wound cavity" or actual damage caused by a projectile is the primary "stopping power" mechanism and that the "temporary wound cavity" or shock wave produced by the projectile is at best a secondary mechanism, if not irrelevant.
^http://www.backwoodshome.com/articles2/ayoob93.html:"This resulted in the FBI Wound Ballistics Workshop of 1988 in Quantico, Virginia. Among those present were Dr. Martin Fackler, head of wound ballistics research for the US Army’s medical training center, Letterman Institute. Fackler had developed an improved ballistic gelatin model that he had scientifically correlated to swine muscle tissue, which in turn is comparable to human muscle tissue. He hypothesized that wound depth was much more important than previously thought, and recommended ammunition that could send a bullet at least twelve inches into his ballistic gelatin."