Firearms Tactical Institute
Tactical Briefs #1, 15 February 1998
We've added a new page "Tactical Briefs". The purpose of our Tactical Briefs page is to sell you ballistic protection for your privates. We're kidding! The REAL concept of this page is to serve as an informal means to announce recent changes to our web site as well as to provide you brief articles of interest and commentary on current events.
We've updated our Wound Ballistics page with information about Duncan MacPherson's book: Bullet Penetration: Modeling the Dynamics and Incapacitation Resulting from Wound Trauma.
AK-47/SKS 7.62x39mm Cartridge Wound Ballistics
Remember the tragic 1989 Stockton (California) school yard shooting in which 35 school children and adults were shot by gunman Patrick Purdy, who was armed with a Chinese Norinco AK-47 type semi-automatic rifle? In response to immense news media exaggerations about the wounding effects of bullets fired from AK-47 type rifles, Col. Martin L. Fackler, M.D., (a former Vietnam combat trauma surgeon) of the U.S. Army Wound Ballistics Laboratory published an article in the Journal of Trauma to correct and clarify the news media falsehoods. Weve located a slightly different version of that article in a very remote location of the web for you. Unfortunately, the article appears to be incomplete, but the portion which has been published is quite informative. Click here to go to Fackler Stockton article.
In light of recent fatal shootings of police officers in Tacoma (Washington) and Portland (Oregon) involving SKS carbines, the 7.62x39mm cartridge WILL NOT penetrate NIJ Level III or IV body armor. The 7.62x39mm cartridge propels its bullet at a velocity of approximately 2400 feet per second. Level III armor stops 5.56x45mm (.223 Remington) M-16 bullets (3100 fps) as well as 7.62x51mm (.308 Winchester) M-14 bullets (2800 fps). Level IV armor protects against steel-core armor-piercing M-1 Garand (30.06 Springfield) bullets (2900 fps). For more information about National Institute of Justice (NIJ) body armor threat level ratings, click here.
Gangsta Shooting Method
In the January 1998 issue of Handguns, gunwriter Massad Ayoob investigates "gangsta-style shooting," a method of shooting being popularized by the entertainment media.
Gangsta-style shooting is an unorthodox one-handed combat handgun stance wherein the weapon is canted 90 degrees from "normal." This unconventional shooting method is appearing more and more frequently in movies and television.
When Hollywood first introduced us to gangsta-style shooting it was met with snickers of derision from firearms instructors and experienced shooters, who quickly recognized it as an inferior technique. However, Ayoob mentions his encounter with an unnamed European armed service that was teaching its personnel to shoot gangsta-style as the technique of choice. According to Ayoob, their reasoning was: "Americans are on top of pistols, and they have their best people as technical advisors for their films, so it must be the thing to do."
Its not uncommon for new shooting students to inquire of their instructors why they arent being taught this specific technique. After all, its new, theyve seen it on TV and in the movies, it looks "wuz-up cuz" cool and cold-killer businesslike, so it obviously must be better than the old fashioned methods!
If youre a firearms instructor, this would be a good handout article for your new students. In it Ayoob conjectures about the origins of the practice, and discusses a few shooting incidents that hes personally aware of in which this trendy street technique was used. He also puts gangsta-style to the test, with very poor results.
Ayoob, Massad: "Gangsta Shooting: Does it Work?", Handguns 12(1): 24-27, 69-71, January 1998.
Wound Ballistics Junk-Science in March 1998 Handguns Magazine
The front cover screams "GIANT Defense Ammo SHOOTOUT!" A quick scan of the Table of Contents and we find "GIANT DEFENSE AMMO SHOOTOUT!" starts on page 26.
Turning to page 26 we discover what turns out to be a six page advertisement for Triton ammunition disguised as an impartial test of various bullets written by bullet salesman/gunwriter Ed Sanow: "Tritons Heads-Up Ammo Demo: A no-holds-barred look at bullet performance". The only thing missing was Sanow and Marshall werent wearing garish "Team Triton" jerseys!
The following is a review of some of Sanows comments in the article. A full review of the article would defeat the concept of Tactical Briefs (this page is meant to present brief, informative items of interest). We could take issue with a great number of his pronouncements, but in the interest of brevity were going to limit ourselves to addressing just a few items.
We hope that as we continuously review selected newsstand magazine articles dealing with bullet performance, youll begin to understand why we refer to this stuff as junk-science.
On page 31, Sanow states:
"The true crush cavity from a rapidly expanding hollowpoint like the Hydra-Shok can be 20 percent larger than that from a slowly expanding hollowpoint like the Winchester Ranger SXT. This is true even though both bullets have exactly the same penetration depth and exactly the same recovered diameter. To base an entire theory of stopping power on the permanent crush cavity from the bullet is inaccurate at best and misleading at worst."
Sanow apparently isnt aware that the erect post of an expanded HydraShok forms a small temporary cavity directly in front of the blunt mushroom-shaped core. The tip of the erect post transfers energy to the tissue it contacts and propels this tissue out of the main path of the bullet during the first few inches of bullet penetration. This tiny temporary cavity actually reduces the diameter of the permanent "crush" cavity because the tip is shoving tissue out of the path of the rest of the oncoming bullet. As a result, HydraShok tends to penetrate slightly deeper than other bullets exhibiting the same recovered diameter and velocity because its directly contacting less tissue during the first few inches of penetration.
The U.S. Navy uses a similar erect post on its submarine launched Trident strategic missile. The post is called an "aerospike," and its function is to push air out of the path of the blunt missile nose to extend the missiles range. In essence, the erect post of an expanded HydraShok bullet functions similarly as a "hydrospike" increasing the expanded bullet's "range" in gelatin and flesh.
Therefore, the scenario Sanow paints in comparing HydraShok and Ranger SXT (formerly Black Talon) is improbable. If both bullets are of the same weight, velocity and recovered diameter, HydraShok will likely penetrate deeper than Ranger SXT, but according to the laws of physics both will crush the same volume of tissue.
Sanow also incorrectly claims that Ranger SXT is a "slow expanding hollowpoint." Hes written elsewhere that Ranger SXT expands gradually during the first eight inches of penetration. This is impossible and untrue. Well address this nonsense in a future Tactical Briefs.
"Any time gelatin testing is done, legitimate differences can result. This is not because one of the researchers is a liar and a fraud. Instead it is likely to be due to different test methods. First of all, calibrated gelatin should be used. The calibration procedure is to fire a .177 caliber BB from an airgun between 575 and 605 fps into the gelatin. This BB must penetrate between 2.75 and 4.00 inches in 10 percent gelatin. Most major researchers, including this author, use calibrated gelatin"
It seems Sanow is trying to explain why some of his data is inconsistent with the results observed by others who are known to calibrate their gelatin. As far as we can determine it appears Sanow didnt calibrate his gelatin until about 1993. This explains why the bullets he was firing into gelatin penetrated much deeper and produced much larger temporary cavities than was observed by scientific laboratories. Bullet velocity and recovered diameter measured by Sanow were consistent with what the others were observing for the same cartridge, but Sanows bullets consistently penetrated several inches deeper. One example is the 9mm 147 grain subsonic. Sanows bullets penetrated more than 17 inches, while laboratories who calibrated their gelatin were measuring an average penetration depth of 13 inches. Another example is the .357 Magnum 125 grain JHP at 1300 fps. Sanow observed this bullet to penetrate approximately 13 inches in his faulty gelatin, while many others measured a penetration depth of less than 11 inches.
Readers need only look at the photograph on page 26 of the Sanow article which shows a .357 Magnum 125 grain JHP that has obviously penetrated more than 12 inches of gelatin. Theres no calibration BB visible anywhere in the gelatin blocks. Compare this photo with data in the table on page 30 "Hollowpoints in Gelatin," which lists the penetration depth of the Remington .357 Magnum 125 grain JHP as 10.6 inches. Why isnt the data consistent with the photograph? Because the photograph is evidence he didnt calibrate his gelatin.
This appears to be a situation where Sanow is asking his readers to believe "everyone else is wrong but me!"
"The real differences in gelatin testing are frequently related to differences in the barrel length and rifling design. Longer barrel handguns produce higher muzzle velocities than shorter barrel handguns. The polygonal rifling used by Glock and H&K produces higher muzzle velocities than the broach-cut rifling used by most other pistol makers. A 4.5-inch Glock 17 has over 100 fps more muzzle velocity with the same 9mm 147-grain JHP than a 3.5 inch Smith & Wesson Model 3913. The result of this increase in velocity is up to five inches less penetration and almost a doubling in recovered diameter. The firearm in use during testing must be stated!"
Again, it looks like Sanow is trying to explain away his faulty data. If bullet velocity is measured and documented, the specific firearm really doesnt matter. Obviously if bullet velocity is different, expansion and penetration are likewise going to be different. If you calibrate your gelatin, your results should be consistent with what others are observing for the same bullet, propelled at the same velocity. The only "real difference" Sanow is quibbling about lays in his use of faulty uncalibrated gelatin.
If the following variables are constant: 1) velocity, 2) expansion, and 3) gelatin viscosity, then bullet penetration should be consistent and reproducible by others. If any "legitimate differences" are observed the apparent cause should be clearly obvious to a knowledgeable researcher.
If gelatin is uncalibrated, then its no longer a dependable "constant." Slight variations in gelatin formulations can introduce errors which cant be detected unless the gelatin is calibrated. A weak solution or a gelatin block that has warmed and softened will not markedly affect bullet expansion, but it will affect bullet penetration and temporary cavity size. Shooting a bullet into water is widely recognized as a quick and valid method for gauging bullet expansion. But because water doesnt duplicate the viscosity of calibrated gelatin or possess the solidity to support a shear force, the bullet is going to penetrate water deeper than in flesh or calibrated 10 percent ordnance gelatin.
Whats unfortunate for Sanow is it appears most, if not all the gelatin data published in his 1992 book Handgun Stopping Power: The Definitive Study is faulty. This defective gelatin data was also apparently used by Steve Fuller to develop his "Fuller Index". If you have a copy of this book (or Sanows and Marshalls 1996 follow-up book Street Stoppers, the Latest Handgun Stopping Power Street Results) look for the telltale presence of a BB in the photos of bullets fired into gelatin. Is Sanow walking his talk?
Sanows exclamation that: "The firearm in use during testing must be stated!" contradicts the entire philosophy of Sanows "one-shot stopping power predictions". He rates the effectiveness/predicted effectiveness of individual handgun cartridges by measuring the wound profiles of bullets shot into gelatin. He then compares the gelatin data with Marshalls "one-shot stop" data and essentially manipulates the data with some gee-whiz formula. What Sanow seems to be saying here is that "one-shot stopping power" is sensitive to the particular gun used, meaning the Marshall/Sanow rating system doesnt universally apply across the board to all guns, including guns of identical barrel length but of different makes! This begs skeptical readers to question: How does the Marshall/Sanow bullet effectiveness rating system apply to my particular gun? Is the stopping power percentage difference 1 percent? 10 percent? Higher or lower? The stopping power ratings list only cartridges, not gun/cartridge combinations.
"The other area of confusion in gelatin testing is the amount of penetration necessary for civilian personal defense and for police patrol duties. A decade ago, two theories existed about ideal penetration range. One was 10 to 14 inches. The other was 12 to 18 inches. These were both only theories. Each side gave credible arguments for its beliefs. In the past few years, the "12- to 18- inch" advocates modified their ideal range of depth to 11.5 to 15 inches. With this concession, very few differences then existed between these two theories."
Weve published a complete list of all the articles printed in the International Wound Ballistics Associations journal, the Wound Ballistics Review. Not one of these articles advocates any change from the 12-18 inch bullet penetration depth recommended by the nations most prominent and respected wound ballistics experts at the 1987 FBI Wound Ballistics Workshop. In 1993, this group met again and unanimously affirmed the principles established in 1987.
Sanows assertion is typical glossing over of facts by broad generalization. Why doesnt he just come out and tell his readers exactly who "modified their ideal range of depth to 11.5 to 15 inches"? If it isnt IWBA or FBI, who are these mystery advocates? Perhaps other "secret sources" he cant reveal to protect their identities? If he eventually identifies who these unnamed "advocates" are, well be sure to contact them to verify the truth for ourselves. Why?
In the early 1990s, Sanow wrote several articles hypercritical of the 9mm subsonic cartridge. He identified, by name, a number of law enforcement agencies whod adopted the 9mm subsonic, and after these agencies experienced an officer involved shooting incident or two they were allegedly dissatisfied with the cartridges "dismal" performance. Several senior law enforcement firearms instructors were so alarmed at Sanows claims that they contacted each of the agencies Sanow cited, and found that hed intentionally misrepresented the facts in his magazine articles. Things just didnt happen the way he said they did. Dr. Martin Fackler, M.D., fully details these findings in his published review of the 1996 Marshall/Sanow book. In addition, Fackler describes in his book review of his own fruitless efforts to track down "statistician Dan Watters from the University of South Carolina" whom Sanow mentions in the book. What Fackler found, or more correctly didnt find, suggests Sanow fabricated this persons existence.
Note: In January 1999 we exchanged e-mail with an individual who identified himself to us as the "Dan Watters" who assisted Marshall and Sanow. Although we've not made any effort to confirm this person's identity, we're satisfied that he is probably the person he claims to be.
Watters stated that he was a student at University of South Carolina at the time he offered to assist Marshall and Sanow. He was pursuing a Master of Arts degree, and was taking a few courses in biostatistics.
Given this information, it appears that Marshall and Sanow intentionally misrepresented Watters' credentials, attempting to pass him off as a professional statistician, which he was not.
Weve reviewed a lot of wound ballistics literature over the last few years, and we believe we might have located one of Sanows unnamed "advocates". Duncan MacPherson, an engineering consultant and member of the IWBA board of directors, authored and published a book in 1994 titled Bullet Penetration: Modeling the Dynamics and Incapacitation Resulting from Wound Trauma. In Chapter 11, Wound Trauma Incapacitation Modeling, MacPherson acknowledges the 12 inch minimum as a standard that "represents the state-of-the-art informed medical opinion" (Medical Issues Summary p261-263). He then comments (p262):
"This creates the apparently curious situation where a requirement (minimum soft tissue penetration of 12 inches) has been set for good reason, but a modest violation of this requirement (e.g., 11.9 inch penetration) still has essentially identical WTI (wound trauma incapacitation) potential. This 12 inch requirement is sound despite the fact that a much lower penetration (e.g., 10 inches) is adequate much of the time, a situation that can cause confusion in trying to reconcile the penetration requirement with WTI assessments."
MacPherson then proposes that its better to select a bullet which achieves an average penetration depth of 15 inches versus a minimum penetration depth of 12 inches. The rationale for his approach is best presented in his own words (discussion points 2 through 5 [p272-273]):
"2) A requirement for a minimum penetration of 12 inches is assumed based on the best available information. This requirement is not a hard requirement, but is a factor in selection of the WTI algorithm. A hard requirement (anything less rates zero) is unsound."
"3) Penetrations up to 15 inches are rewarded for several reasons. By far the most important reason is that an average penetration of 15 inches ensures that the minimum penetration will be at least 12 inches, and the average is easier to demonstrate in empirical testing than the minimum. In addition, penetration beyond the 12 inch minimum has value in penetrating unusually large torsos (whether corpulent or muscular); this scenario is not common, but is by no means unheard of. Finally, a deeper penetration produces somewhat higher velocity at every penetration depth, and blood vessels are at least somewhat more likely to be ruptured by grazing bullet impact at higher velocities...."
"4) Penetration depths greater than 15 inches are not rewarded because these penetration depths are almost always beyond the vital structures in the target body."
"5) Average penetration depths less than 13 inches are penalized to discourage JHP bullet designs with inadequate or marginal penetration. The penetration factor in Figure 11-1 gives a relative rating of 100% for an average penetration depth greater than 13 inches; a 13 inch average penetration will usually place almost all of the penetration distribution beyond the desired 12 inch minimum. An average penetration depth of 12 inches (which will meet the 12 inch minimum on only half the shots) has a relative rating of 80%. This rating is a reflection of the fact that the penetration variation is small enough to make the total penetration depth distribution close to 12 inches, and also that penetration slightly less than 12 inches is adequate in many cases. An average penetration depth of 10 inches will seldom have a shot meeting the 12 in minimum and is rated at 40%. An average penetration depth of 8 inches is totally inadequate and is rated 0%. This evaluation is somewhat subjective and potentially argumentative, but seems to give an emphasis consistent with accepted medical opinion; JHP bullets designed to maximize performance on this scale will have adequate penetration."
(Our apologies to Mr. MacPherson for excerpting such a large amount of his text, but we felt it better to present his rationale in his own words rather than attempt a weak interpretation.)
This might very well be the source of Sanows claim. However, if it is, then he either profoundly misunderstands what MacPherson is saying, or hes intentionally misrepresenting MacPhersons position.
Sanow proclaimed in a 1992 Handguns article that he determined the best penetration depth for optimum stopping power was exactly 13.3 inches. This was the penetration depth he measured for the .357 Magnum 125 grain JHP cartridge in his uncalibrated gelatin. Oops! That was identical to the penetration depth measured for the 9mm 147 grain subsonic by reputable researchers who calibrated their gelatin. Now that he claims to be calibrating his gelatin, we understand hes modified his optimum penetration depth to somewhere between 8 and 9 inches (this figure might be incorrect, but were not going to thumb through a pile of Handguns since the exact figure is irrelevant to the point were trying to make). Since 1987, the FBI standard of 12-18 inches of penetration has remained unchanged. Whos conceding here?
As we mention on our wound ballistics page, the basics of bullet performance and wound effectiveness are pretty easy for ordinary people to understand. So easy, that theres really not much to write about once the facts are laid out. The problem for newsstand gun magazines is that once these simple facts become common knowledge among their readers, theres really little point in publishing articles which do nothing more than report how deep a bullet penetrates and how big it is when its recovered. After awhile, readers will lose interest reading such incredibly boring facts. So, to liven things up some gunwriters and editors have resorted to inventing controversy. And as youve read here, when you manufacture controversy theres plenty to write about!
When newsstand gun magazines are your sole source of information about bullet effectiveness, your ability to thoughtfully consider and evaluate the validity of the information being presented to you is extremely limited. You end up believing whatever it is you're told simply because you don't know any better.
Ed Sanow is, in essence, a bullet salesman. Does he have a financial stake in the articles he writes? If Ed Sanow were a used car salesman, would you be so willing to believe everything he told you or would you check things out for yourself?
Knowledge is the battery which powers your bullshit detector. If the initial charge is weak or the battery never installed, the alarm will never sound when it should.
Sanow, Ed: "Tritons Heads-Up Ammo Demo: A no-holds-barred look at bullet performance." Handguns 12(3); 26-31, 75. March 1998
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