Recent content by Michael Courtney

An anonymous poster with the handle "Odd Job" Wrote: We have made some efforts to make our work understandable to the layman, but we've had an awful lot published in scientific venues for you to suggest that our work has been rejected by the scientific community. On the contrary, the...

Come on Ryan, you should at least try a google scholar search before floating the hypothesis that our ballistic pressure wave work has not gained the credibility needed for publication in scientific venues. Several important papers were published in 2007, including Links between traumatic...

Ballistics Testing Group 2008 Publications We appreciate the thoughtful discussions and valuable references provided by forum members over the years, and we are mindful of the regular requests by forum members to keep them appraised of our ongoing work. We’ve been busy in 2008, as attested...

I think we all hope that we would have the faith or the courage or whatever is necessary inside of a man to do the right thing under the circumstances. The bigger question is whether or not each of us will do the right thing under our present circumstances. A lot of men today won't even...

The retarding force between bullet and tissue is the key parameter when understanding the potential for distant injuries. The attached figure shows a plot of retarding force vs. penetration for a 30 caliber bullet in ballistic gelatin. (This figure is Fig 4-9 in the Textbook of Military Medicine...

How many bullets with 100 ft-lbs of energy get stopped by direct hits to the breastbone that have not already lost a lot of energy passing through intermediate barriers or thick clothing? I bet you can't cite any published examples to support your myth of the breastbone's stopping power. Auto...

I can definitely see both sides of this one. On the one hand, discretion is mandatory is many situations and highly recommended in many others. On the other hand, there are many negative stereotypes about folks who carry guns, and people can often benefit from the knowledge of a few...

Actually, Bo Janzon, who wrote a number of important papers supporting the importance of energy transfer, has a master's degree in Engineering Physics and a PhD in Medical Science. His work is highly esteemed in the field of wound ballistics, and much of it is incorporated into the Textbook of...

One of many myths in wound ballistics is the idea that normal bullets cannot exceed the speed of sound in tissue. As pointed out in the Textbook of Military Medicine, The speed of sound in the lungs is roughly 50 m/s. Michael Courtney

Only a small fraction (< 10% in most cases) of the bullet's kinetic energy is absorbed by expansion and/or fragmentation of the bullet. The retarding force between bullet and tissue is exactly equal to the local rate of the projectile's kinetic energy loss. This is the force that is...

The relevance is mostly related to desig and selection of ammunition. There is a growing body of evidence that indirect effects can hasten incapacitation for levels of energy transfer near 500 ft-lbs, but the local rate of energy transfer (rather than the total energy transfer) seems more...

Lots of people experience mild concussions (sports injuries, for example) with no noticable long-term effects. Most survivors of well-placed penetrating rifle wounds to the chest are cases where energy transfer is minimal because the bullet does not tumble, fragment, or expand. The...

It seems that one of Fackler's mistaken presuppositions is that there has to be macroscopic movement of tissue for there to be an injury of physiological dysfunction. In other words, he focused on direct crush and stretch as injury and ignored the possibility of compressive or microscopic shear...

The value of sound reasoning in print is a lot like the value of real estate: Location, Location, Location. Mr. Williams has the gravitas to make the message heard at the right place and at the right time. Michael Courtney

The Textbook of Military Medicine has a lot of useful information on wound ballistics. http://www.bordeninstitute.army.mil/published_volumes/conventional_warfare/conventional_warfare.html Chapter 4 is particularly useful for understanding wounding effects, but all the chapters on...