Go Big or Go Home: A Look at the Science Behind Firearm Wound Potential

Before beginning this piece on wound potential of various calibers, I opened a few notebooks and studied the subject again. I ignored reams of paper put out by gun writers but rather concentrated on the works by gentlemen with titles such as doctor, colonel or general. Vincent DiMaio,  Dr Martin  Fackler, John T. Thompson and Colonel Louis LaGarde are among some of the most authoritative experts through the years, so I looked at their work cataloged at the federal level not the newsstand. By federal level, I mean testing performed by the U.S. Army and FBI under careful test conditions. The time period ranges from about 1900 to the present day.

I have long studied the tactical implications of gunfights, which I find important to overall defensive knowledge, but the wound potential of each caliber and load is also incredibly vital to understand. I have taught wound ballistics in an institutional setting. There are well-documented scientific studies that shed much light on the subject. The most recent were conducted by the FBI. In the previous century, the U.S. and British militaries also conducted thorough tests. Each of these studies met the test of science. They were valid, well done, repeatable and verifiable.

In contrast, a generation ago, the popular press published a number of so-called stopping power studies as well. The methodology was questionable at best and the results often unverifiable and even unrepeatable. The editors who published these studies had no background to distinguish between a hoax and science and evidently did not care as long as it kept readership buying. If in fact the events described took place—and that is a big question mark—the results were invalid as the methodology was bankrupt. As an example, only events in which one shot was fired and connected were included. This makes small calibers look much better if the results of that one bullet performed well during that one test.

Science vs. The Popular Press

I remember there were, at one time, reports in a magazine of a so-called goat test in which wired or tethered goats were shot to see how the ballistics performed striking actual tissue and bone. Stories like these that appeared in enthusiast publications had little to no impact on professional opinions save as comic relief among serious study. But some of my students brought that rubbish into the classroom. I told the young police officers I would simply apply the rules like a small-town magistrate court. Prove the events occurred, and we would discuss them. It never happened. They could never offer any proof short of this is what the author said. Among the most respected writers of that generation was a man you may have heard of, Colonel Jeff Cooper. He did not place much stock in these so-called studies either. Cooper was a preeminent firearms instructor, and also a writer who never struck an off key or played a bad note.

The so-called studies purported to gauge the effect of various calibers in actual cases where they stopped actual felons in their tracks, providing unscientific, yet anecdotal evidence of the stopping power of some smaller calibers. Not stopping at the propagation of misplaced faith in calibers such as the .32 ACP and .380 ACP, the pundits and editors even assailed the records of such experienced warriors and gunfighters like Sgt. Alvin York and Wild Bill Hickock.

I know for certain that a Congressional Medal of Honor isn’t awarded without a great deal of investigation, so York’s exploits with a firearm were well-documented and affirmed. As for Hickock, well, no one would have delivered a slander to his face when he lived would they? He knew his way around a firearm.

Controversy Through History

When using history to support arguments for the lethality of calibers, you must infer some things from the data available. For instance, wound potential seemed not to be a subject of study until about 1900. The .44- and .45-caliber service revolvers simply worked and dropped both men and horses well. The .44 cap and ball in particular earned a reputation for lethality during the Civil War. A dead soft .457-inch ball expands aggressively in living targets. The .36 Navy was effective at close range as its .380-caliber soft lead ball expanded and made a serious wound. The more ballistically efficient Minie ball traded off a lot of wound potential.  The pointed Minie Ball traveled further and shot flatter due to a flat base and pointed nose. But its wound potential was diminished due to this shape. It did not plump up like round balls upon impact, creating a larger, and thus more lethal, wound cavity. This made for the first wound potential controversy!

Then came smokeless powder and a move to more aerodynamic, elongated pointed bullets. Usually harder than the older soft lead balls, these loads were far from effective in small bores. The U.S. military adopted a .38-caliber revolver that delivered miserably ineffective results. After the initial debacle, the .38 was replaced with .45-caliber revolvers as a stop gap, simply because they were bigger and delivered more energy to their target. A study of handgun calibers was eventually undertaken that led to the adoption of the .45 ACP cartridge. In its own way, the test was as important as the U.S. military trails leading to the development of the 1911 pistol. These tests  were undertaken to determine that caliber the the Army would find most efficient and deadly. Settling on a .45-caliber round, they adopted a self-loading pistol that would chamber this caliber.

The U.S. Army conducted a series of tests in 1904. The Thompson/ LaGarde testing was undertaken to explore the effect of handgun bullets on cadavers and live animals. The tests are often used to point out the superior effect of big bore handguns and was instrumental in the adoption of the .45 ACP cartridge. But shooting slaughterhouse bulls and cadavers was more than about the .45 caliber’s capabilities. Colonel John Thompson and Dr Lous LaGarde qualified the factors that affect wound potential. While shooting the dead is gruesome much was learned from the autopsy. Caliber or bullet diameter, bullet weight, velocity, bullet profile, stability, tumbling and angle of impact all play a role in how lethal a round is. The path of each bullet was carefully documented in this study.

Controlling Results

We cannot control and easily measure such factors as they occur in a moving fight against an adversary who may not be stabilized and is moving or who may be firing at us. This makes for an uncertainty principle in wound potential. These studies are far more valid than the modern unprofessional stopping power studies by amateurs. On the other hand, modern lab testing, which involves firing into gelatin blocks and measuring the total wound and total area affected, is measurable and repeatable. Agreed, not all factors are covered in gelatin testing, such as bone and muscle density, but they are a reasonable device for study. Gelatin testing in controlled conditions is preferable to a hodgepodge of uncontrolled events. A reasonable person would choose a handgun with respectable wound ballistics and a balance of controllability. For most of us this means a 9mm, especially if our practice schedule is limited. A .45 ACP is good for those willing to invest more time and effort in learning to control the piece. So is a 10mm or .357 Magnum a good choice. But only if you are able to control the caliber.

The Thompson LaGarde test validated the superior effect of .45-caliber handguns over high-velocity small bores. The .30 Luger and 9mm Luger—all were tested with nonexpanding bullets—were dismal on live animals. But Colonel Thompson did note one area in which the high velocity small bore calibers were superior, and this passage of the test is often overlooked.

When fired into the skull of cadavers—and skulls are thick and solid as bones go—the .30 Luger and 9mm Luger produced extensive damage from secondary fragments and penetration. The .45s were not as impressive in this scenario. The difference was profound.  High velocity shattered bones and produced fragments.

This reminds us of WDM Bell’s experience with the .30 Mauser. (Bell was among the most famous African hunters ever, a man of vast experience against both men and animals. He also served in World War One.)  A far more powerful cartridge than the .30 Luger, the Mauser cartridge was generally effective when it hit bone.

Back to the Thompson LaGarde testing and trials. These were far-reaching tests of several handgun calibers that evolved in the military trials of the .45 ACP cartridge. Thompson recommended that handguns be issued with cup point “manstopper” bullets as they were capable of generating larger wounds and more rapid blood loss. Finally, Thompson noted that while the big bores were more effective than the 9mm or .38, nothing short of a “75mm field gun” could be counted on to drop an enemy with a single shot. That said, don’t neglect the recommendation of the .45 ACP based on the proven, well-documented performance of the .45 Colt cartridge in that time. There was no question of the lethality of that war dog. At the time, war horses and jaguars were a concern, and the .45 ACP was designed to deal with these threats.

Another finding of the Thompson LaGarde shooting tests was that flat-nose bullets with a blunt profile were superior in creating wounds. A round-nose projectile would sometimes skid off bone depending on the angle. A flat-nose bullet is more likely to break the bone. The examination of wounds in cadavers also found that damage to blood vessels and tissue is greater with a flat-nose bullet.

Elmer Keith’s semi-wadcutter design was yet to come, but it would prove a seminal design for handgunners. When I began my study of physics and mathematics, I began with Pythagoras and studied Kepler and Newton. I don’t find the Thompson LaGarde test invalid at all. Taken as a whole it is a complete and well-documented study in wound ballistics.

Colonel Thompson was also an early advocate of fully automatic weapons who went on to invent the Thompson submachinegun. He sometimes overshadows Dr. LaGarde.

Dr. Lagarde was a Colonel in the Army Medical Corps, a decorated officer who saw much action in Custer era campaigns and in private practice. It is less well known that Dr. LaGarde was in charge of studying wound ballistics of the new .30-40 Krag rifle cartridge and later the .30-03 and .30-06 high-velocity cartridges in which he contrasted these calibers to the black powder era .45-70. His work was published in a report from the Surgeon General in 1893. He also presented his work at the Pan American Medical Congress.

A Crazy Quilt of Observations

In my life, I have learned wound ballistics from many sources. A rich source for information on wound potential comes from ranchers, farmers and outdoorsmen. You run across many different opinions that must be taken at face value in some points and with a grain of salt in others. Some don’t find .32s or .38s effective against a jackrabbit. A military veteran once told me pistols are good for shooting dogs and nothing larger. As for deer, well, deer are about the same size as a man and about as hard to put down. Men are more susceptible to shock, however. As we often said in police work, don’t be the man in the other chair. It usually meant the man in the defendant’s chair in the court room but can mean other things, and it is never good. I wish to be on the side of research, education and reputable testing, not junk science.

A fantasy that is hard to kill is that .22s bounce around in the body. I have been on hand taking reports in the emergency room after folks were shot in the torso with a .22. One was a friend. None bounced in the body. I have seen quite a few autopsy photos. I have also shot animals up to coyote size in the field, not in a lab. From a rifle, the .22 doesn’t bounce around inside the body.

I can also confirm after tests in water and gelatin and also in correspondence with a NYCPD detective, the .45 Colt, in its original 255-grain form, does tumble. I have in my file a hodgepodge of information of interest and some is pretty bizarre.

• A cop is shot at thinks he is shot and kills his attacker—the cop is groaning in agony but not actually wounded. The shot missed.
• An entire agency wiped out by a .32 ACP pistol—well both officers at least. It does happen but doesn’t suggest the .32 ACP is a great defensive choice.
• A fellow actually plucking .38-caliber bullets out of his midsection with his fingers after he is shot (an old break top .38 S&W—146 grains at 560 fps as tested.)
• An FMJ .45 spins around a skull and exits without killing the victim.
• A .44 Magnum to the knee rips bone and cartilage from the appendage, crippling the man for life.

But all of these instances make up such a crazy quilt of results that I would never foist such an assemblage of events on a student seeking to determine what is the best load for delivering threat-stopping wound potential. Laboratory testing is repeatable and verifiable. It can be cross-checked and the results compared. Based on such study, I cannot recommend any caliber below .38 Special or 9mm Luger for personal defense. But that is no surprise. It is your hide, but I suggest everyone make their choices based on reputable testing and results.

Final Thoughts

I am not a ballistician or engineer. My degree is in police science and psychological study. I am an interested student of wound ballistics. I don’t pretend to be a final word but take any recommendation up the logic ladder and see how many rungs it will climb. Consider reliability, accuracy and a clean powder burn when choosing calibers and the ammunition you will use in your chose caliber. The choice you make could literally be a matter of life or death…your life or death quite possibly.