Dr. Fackler's report, compiled for the Letterman Army Institute of Research, is not meant to be a light read, but has been cited in its entirety to give context. Several points proven by Dr. Fackler are, I believe, worthy of note-and applicable to big game hunting terminal ballistics.
It has been mentioned before, but the primary component in quick lethality is the size of the permanent wound cavity-naturally "in the right spot." The importances of the "temporary cavity" and the projectile velocity have been overstated. The importance of bullet weight has been underrated in the literature.
The "pressure wave" precedes the projectile, and does not cause the spectacular damage many ascribe to it. The notion of "kinetic energy deposit" is likewise over rated, and is a comparatively minor factor in quick lethality. As Dr. Fackler states, "They are l) sonic pressure wave, 2) heating of the tissue, 3) heating of the projectile, 4) deformation of the projectile, and 5) motion imparted to the tissue (gelatin bloc displacement for example)." All of these factors are energy deposit components that do not cause tissue damage alone.
As far as energy use theories, cutting tissue is better than crushing, and crushing is better than temporary cavity "creation." When a bullet becomes non-aerodynamic, tissue damage increases due more to surface area striking that tissue. Dr. Fackler mentions that "Duct-sealing compound, clay, soap, gelatin, and water-soaked phone books or newspapers are commonly used tissue simulants." None are of accurate predictive value in determining performance on living animal tissue. The worst offenders being non-elastic tissue simulants, "that give a false impression that these cavities represent the potential for tissue destruction rather than the potential for tissue stretch. The latter may be absorbed by most living tissues with little or no lasting damage."
Dr. Fackler further comments, "Recognizing the projectile-tissue interaction as a simple mechanical collision and comprehending how tissue is disrupted (crush and stretch) in this collision, coupled with wound profiles illustrating how much crush and stretch occurrs at any depth of projectile penetration, should give the reader sufficient background to recognize any perpetuation of past errors or creation of new ones in the future. It is not surprising that attempts to teach wound ballistics using formulae or tables of velocity and kinetic energy have been counterproductive. These methods have diverted attention from the actual tissue disruption and made the subject appear unnecessarily complicated."
As applied to the Savage 10ML-II, I want a relatively heavy for caliber bullet with positive expansion and virtually 100% weight retention capability. I want cutting and crushing of tissue, and the largest possible permanent wound formation in the vital area of the game animal. This best describes only one genre of bullet; the Barnes MZ-Expander in the heavier weight offerings.
Too often we believe "down is dead," when down is only down. Distances and minutes until expiration become anecdotal evidence, consisting of steps not verified range, and often instant "Dead Right There" has been revealed to be a 35 yard run (or more) on video. Perhaps muzzleloaders will one day take better note of Dr. Fackler's research, which he feels has been often misrepresented and ignored?
Email: randymagic@aol.com
© 2005 by Randy Wakeman
