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Tactical Briefs (Volume 2, Number 3)Novak Sights Combat Hardware or Fashion Accessory?
The evolution of snag-resistant rear sights for automatic pistols has mutated from no-nonsense combat functionality to absurd fashion designs that are meant to be appealing to the eye.
Novak and Kimber sights are examples. The contours of these two rear sight designs, Novaks gentle forward slope and Kimbers trendy curved jump-ramp shape, do not permit an injured combatant to snag the rear sight against a readily available object to retract the slide with one hand, if necessary to clear a stoppage or chamber a round.
The purpose of snag-resistant sights is to reduce the possibility that the gun will hang-up on clothing when its drawn from its holster. Removing a gun from a holster is usually a backward motion, and this means that the rear and side surfaces of the sight should be suitably contoured to avoid snagging on clothing. Why then are the front surfaces of these sights more snag-resistant than need be?
While an automatics slide can be manipulated with one hand by snagging the front of the slide against an object and pushing forward on the grip, this technique is not as efficient or readily employable as with the rear sight snag technique. Ditto with the technique that snags the slides ejection port edge.
(The slide of many large frame handguns can be pressed into the meaty part of the thigh to produce enough friction to retract the slide. Compact handguns intended for concealed carry generally require more effort to retract the slide. Therefore the capability to snag the rear sight is more important with compact handguns.)
A rear sight with a steeply angled front surface can be snagged against a leather belt, the top of a back pocket, a belt loop or the edge of a shoe sole to work the slide with one hand. These objects are usually available on the person. The technique can be quickly performed without the need to desperately search for a suitable object nearby to snag the slide while under attack. Novak, Kimber, Heinie Slant Pro and several other snag-resistant rear sight designs cant be utilized in this manner.
With combat hardware, tactical utility takes precedence over good looks.
Environmentally Friendly M16 Bullet Developed by U.S. Army
The U.S. Army's Picatinny Arsenal has recently developed a new lead-free 5.56mm bullet. It consists of a tungsten-tin core covered by a copper jacket.
Hopefully this new bullet will be used for training purposes only, because it probably will not fragment like the current M855 cartridge does at distances under 100 yards. We're unaware of any wound ballistics testing that has been performed with this new politically correct bullet.
When the M855 bullet yaws and fragments, the holes peppered in soft tissues by the fragments work in synergy with the temporary cavity to substantially increase the bullet's wounding effects. (We'll be publishing a wound profile illustration of the M855 cartridge soon.)
It's doubtful that the new tungsten-tin bullet offers similar terminal performance. If our prediction is true, its wounding effect will be less than a 9mm FMJ bullet. This environmentally friendly bullet might very well be "enemy friendly" too. Use of this new bullet in combat could result in unintended negative consequences for U.S. ground troops.
Click here for more informationA Discussion of Classic Wound Ballistics Myths
Myth Number 1: Ordnance gelatin testing is used to predict bullet effectiveness.
A common misconception about ordnance gelatin testing is that it can be used to predict the effectiveness of personal defense ammunition. It cannot.
Testing bullets using standard ordnance gelatin as a soft tissue simulant provides useful information about a bullet's terminal ballistic mechanical performance and wounding effect. Thats all. These two attributes are directly linked to the bullets design, construction and velocity. They are defined as follows:
Terminal ballistic mechanical performance is a measure of bullet penetration, expansion, fragmentation and yaw at a given velocity.
Wounding effect is the disruption produced by a bullets terminal performance characteristics.
To be "effective" a bullet must inflict an injury that produces dysfunction of the central nervous system. This is accomplished by one of two mechanisms: 1) direct physical damage to a central nervous system structure (the bullet must penetrate the brain or cervical spinal cord), or 2) blood loss in quantity to rapidly deprive the brain of the oxygenated blood it needs to remain conscious (the bullet must penetrate a major cardiovascular structure).
Consequently, wound effectiveness is a function of what tissues (vital or non-vital) are disrupted by the wounding effects of the bullet. Wound effectiveness is dependent upon where the bullets wounding effects are located in the body and what tissues are involved.
Therefore, when a bullet is shot into ordnance gelatin, the only traits that can be quantified are the bullets terminal ballistic mechanical performance characteristics and wounding effects. Gelatin does not reveal "how effective" a bullet is, because "effectiveness" is a result that cannot be measured in a test medium.
Wound effectiveness is a consequence of shot-placement (the bullets path through the body) and penetration.
Myth Number 2: The Fackler-IWBA Stopping Power Theory is "Deep Penetration"
This classic piece of disinformation has been promoted by gunwriters Ed Sanow and Massad Ayoob since the early 1990s. Sanow and Ayoob frequently paraphrase: "According to Fackler-IWBA, if penetration is everything, the 9mm FMJ cartridge should be one of the most effective loads on the street."
Sanow, Ayoob and other gun-writers who make this assertion are either uninformed or dishonest.
The Fackler-IWBA concept of rapid incapacitation is about DISRUPTING VITALS.
According to Fackler-IWBA, rapid incapacitation is a function of damaging or destroying tissues that are critical to an attackers immediate survival. Consequently, the bullet must pass through vital structures to be effective. If the bullet does not pass though major blood distribution organs or the central nervous system, it will not dependably force an attacker to quickly collapse.
To reliably accomplish this task, the bullet should be capable of penetrating deeply enough to reach and pass through vital structures in the body from any angular aspect. This capability is called adequate penetration.
Fackler-IWBA recommend a minimum of 12-inches of penetration. This 12-inch minimum penetration performance guideline is meant to ensure that the bullet has adequate penetration potential to reach and disrupt vitals. Thats it!
The 12-inch minimum penetration performance guideline ensures the bullet has sufficient penetration potential to reach and pass through vitals; not only when penetration conditions are favorable, but unfavorable as well, such as when a bullet has to perforate arm muscle and bone before it enters the upper torso.
An arm obstructs about 20 percent of the torso when it is outstretched and pointing a gun, and you're shooting at the bad guy from a front angle. Likewise an arm can obstruct 50 percent or more of the torso when you engage a bad guy with gunfire from a side angle. Therefore theres a good chance that your bullet could hit an arm, and thats part of the rationale behind the 12-inch minimum penetration performance guideline.
(Pre-fragmented bullets like MagSafe and Glaser are easily defeated by an arm, and this is why we feel they're inadequate for personal defense use. Any pellets that manage to exit the arm and penetrate the torso are going to produce minimal wounding effect. Pre-fragmented bullets require best case conditions to produce maximum wounding effect.)
The minimum penetration depth guideline recognizes that combat is chaotic, and it is meant to eliminate tactical uncertainty that a well placed shot will be defeated by common obstacles such as an arm or an unusual shooting angle that requires the bullet to negotiate several inches of non-vital tissues to reach and damage vitals. 12 inches of penetration provide a margin of safety in situations such as these.
Penetration doesnt mean a thing unless vitals are damaged and destroyed. A deep penetrating bullet that plows past vital structures without going through them is just as ineffective as a shallow penetrating bullet that stops an inch short of the heart.
The intent is to optimize a bullets wounding efficiency by striking a balance between adequate penetration and reliable expansion.
Lets examine Ayoobs and Sanows absurd assertion about the effectiveness of 9mm FMJ ammunition: A 9mm FMJ bullet, with its smooth, semi-pointed, streamlined shape is less efficient in crushing tissue than an expanded hollowpoint bullet. A round nose FMJ bullet crushes a permanent cavity in soft tissue that averages approximately 66 percent of the bullets diameter.1 Whereas the blunt, non-aerodynamic shape of an expanded JHP bullet crushes a permanent cavity that averages approximately 82 percent of the bullets expanded diameter.1 A 9mm FMJ bullet that penetrates the heart is not going to produce as effective a wound as a 9mm JHP bullet which has expanded to .60 caliber that penetrates the heart. The rate of blood loss through the hole produced by the FMJ is not going to be as fast as the hole produced by the expanded JHP. Therefore the FMJ bullet's wounding efficiency is inferior to the JHP bullet.
The Fackler-IWBA concept is not "deep penetration." Penetration is a terminal performance characteristic that does not determine "effectiveness."
The Fackler-IWBA concept is disrupting vitals to produce rapid and reliable incapacitation.
- MacPherson, Duncan: "Table 8-3: Projectile Penetration Model Parameters, ø (Bullet Shape Factor)," Bullet Penetration, Ballistic Publications, El Segundo, California, 1994; pp. 205.
Myth Number 3: Street Results
The Fackler-IWBA "stopping power theory" of disrupting tissues that are critical to immediate survival will usually result in the immediate death of the bad guy. According to Fackler-IWBA this is the only method that quickly and reliably stops determined homicidal attackers. If the bullet doesnt disrupt these structures, it wont produce the kind of wound trauma needed to unfailingly and quickly stop an assailant.
A good stop, a shooting that meets Fackler-IWBA incapacitation criteria, will most likely produce the death of the bad guy. He/she will be dead on the scene.
A failure to stop can be defined as a shooting to the body in which the attacker survived long enough to make it to a trauma center for medical treatment. Blood loss was not rapid enough to force the attacker to quickly collapse unconscious. Blood loss in the required quantity to achieve rapid incapacitation is usually fatal. (This failure to stop criteria excludes an attacker's psychological reaction to being shot or shot at. Psychological reaction includes, but is not limited to, involuntary fainting, compliance, fleeing, falling down, etc. In this context, failure to stop simply means that the injury inflicted was insufficient to compel the attacker to involuntarily collapse from physiological dysfunction.)
Therefore, real-world street results of bullets that meet Fackler-IWBA criteria are only going to tell you how successful a combatant was in achieving good shot-placement. Good shot-placement (vitals penetrated) will produce a good stop. Poor shot-placement (non-vitals penetrated only) or good shot-placement using a bullet design with poor wounding efficiency (full metal jacket or a small caliber bullet), will produce a failure to stop.
The Fackler-IWBA criteria ensures that the bullet provides you a combat capability to stop an attacker not only when conditions are most favorable (front to back shot through the sternum), but also when conditions are most unfavorable (the bullet has to penetrate several inches of non-vital tissues to reach and pass through vitals).
The requirement that a bullet must pass through vitals and will most likely produce a fatal injury is a combat capability, which should not be confused with the legal and moral issues of 'shooting to stop.' This deadly force combat capability is the only means to reliably stop an attacker, according to informed medical opinion.
Shot-placement and adequate penetration are the two primary elements of the Fackler-IWBA 'stopping power' criteria. Both are equal in importance.
In summary, the Fackler-IWBA concept of 'stopping power' requires the bullet to pass through a major blood vessel of the body, the heart, the brain or the cervical spinal cord. Permanent wound trauma to these structures disrupts the functioning of the central nervous system, either by depriving it of oxygen from rapid fatal hemorrhage or direct physical destruction of the central nervous system itself. Theres no inexplicable voodoo involved that will somehow reveal itself from 'street shooting statistics.'
A valid study of actual handgun shootings will simply tell you if the bullet perforated vitals or not, and this is independent of bullet design. It will confirm that most 'stops' are the direct result of a psychological reaction to being shot, and whether the reaction was voluntary or involuntary. Such a study can also provide feedback as to the accuracy of bullet terminal performance and wounding effects as observed in ordnance gelatin testing.
"Small-Caliber Defense Loads: Are Any Effective?" Dick Metcalf, Shooting Times, 40(3), pp. 94-99; March 1999
This article is a well-meaning attempt to quantify the terminal performance of various .22 Long Rifle, .22 Magnum, .25 ACP and .32 ACP cartridges when fired from small pocket pistols. Sadly the criteria used to determine "load effectiveness" is unique and ill conceived, which produces absurd conclusions.
Throughout the article, Metcalf repeatedly uses the term "effectiveness." His basis for determining "effectiveness" is to shoot three bullets into calibrated ordnance gelatin. As we described in the preceding article, ordnance gelatin cannot be used to determine "effectiveness." Ordnance gelatin is used to measure terminal performance and wounding effect. "Effectiveness" is a product of what tissues are disrupted by the bullets wounding effects (permanent and temporary cavitation), and is a consequence of the bullets penetration path through the body.
Metcalf states that he used "calibrated ordnance gelatin" in his tests. Unfortunately he doesnt indicate what calibration tolerance he used nor did he include the calibration data with his terminal performance data. We speculate that he used a simplified 20-percent calibration tolerance, which is the same standard as used by gunwriter Ed Sanow. The inclusion of gelatin block calibration data is important. It indicates to readers whether the block calibrated in the low or high tolerance range, and allows readers to adjust their interpretation of terminal performance data accordingly.
The FBI also does not give details about gelatin block calibration data in its reports. However, the FBI tests cartridges using five individual "calibrated" gelatin blocks per test event. The quantity of gelatin blocks used permits a reasonable examination of terminal performance because some blocks will calibrate high and some will calibrate low. Calibration scatter among individual gelatin blocks produces a self-correcting averaging of results.
We speculate that Metcalf shot more than one bullet into each gelatin block. In the absence of reporting calibration data, theres no calibration scatter that will "average-out" his results. All bullets shot into a gelatin block that calibrated in the high tolerance range will actually penetrate standard gelatin less deeply than reported. Bullets shot into gelatin blocks that calibrated in the low tolerance range will actually penetrate standard gelatin more deeply than reported. But theres no information to permit this interpretation by his readers.
Standard "calibrated" gelatin is gelatin that exhibits 8.5 centimeters penetration by a standard steel BB with an entry velocity of 590 fps. A 20-percent calibration tolerance (8.5 ± 1.7 cm [approximately 3 3/8 ± 5/8 inches]) means that the BB can penetrate anywhere between 6.8 to 10.2 centimeters (approximately 2 3/4 to 4.0 inches) and the gelatin block is considered acceptable. However this means that bullet terminal performance will also be plus or minus 20 percent.
It is rare for a gelatin block to calibrate at exactly 8.5 cm. If the BB penetrates less than 8.5 cm, bullets shot into the gelatin will penetrate less. If the calibration BB penetrates deeper than 8.5 cm, bullets shot into the gelatin will likewise penetrate deeper.
How important is calibration information? Consider the hypothetical penetration performance of a bullet that consistently penetrates an average of 10 inches deep in a block of ordnance gelatin that calibrated at exactly 8.5 cm (3 3/8 inches). If the same bullet is fired into a block of gelatin that calibrated at the extreme low range (6.8 cm [2 3/4 inches]) it would penetrate approximately 8 inches (a 20 percent difference). If the same bullet is fired into a gelatin block that calibrated at the extreme high range (10.2 cm [4 inches]) the bullet would penetrate approximately 12 inches deep (a 20 percent difference). A 20 percent calibration tolerance range can produce errors as large as 40 percent between individual blocks of "calibrated" ordnance gelatin.
The simplified 20 percent calibration tolerance is a method that has been obsolete since 1994, when IWBA member Duncan MacPherson developed and published a calibration correction procedure.1, 2 This correction method allows adjustment of bullet penetration depth to an accuracy of within 3 percent of the calibration standard.
Had Metcalf reported calibration information in his article, interested readers could have independently verified his terminal performance results very easily. As published, the disparity of Metcalfs terminal performance results can be as extreme as 40 percent in each cartridge category tested.
Metcalfs criteria for determining "effectiveness" (wound surface area) is indeed creative. His method is far more complex than necessary, and is based on classic misinformation. On page 96, in the sidebar titled "Judging Load Effectiveness," he describes his method:
"Quick blood loss is critically important to incapacitating a violent target. When blood pressure drops to zero, the heart stops beating and the brain stops working very quickly. For that reason most experts feel large wound surface areas generated by deep penetration with controlled expansion are more significant than merely large wound volumes caused by shallow penetration of rapid-expansion projectiles because deeper penetration encounters more critical blood-transmitting organs and tissues. (Our emphasis.) Of course, the two are clearly related. In general, the bigger the wound volume, the bigger the surface area, and vice versa. But the figures are not directly proportional; a deep, skinny wound may have a greater total surface area than a shallow, wide wound of equal volume.
In my evaluations I determined the average projectile upset diameter for each recovered bullet by making four cross-sectional measurements with the largest and smallest as the extremes and employed that figure to calculate frontal surface area. Wound volume, the size of the wound channel in cubic inches, was calculated for each load by multiplying the average frontal surface area of the recovered bullets by the average depth of penetration. Wound area, the internal surface area of the wound channel in square inches, was calculated for each load by multiplying the average circumference of the recovered bullets by the average depth of penetration...."
The italicized passage in the first paragraph is an incorrect statement. Rapid incapacitation is not a matter of "deep penetration;" its a consequence of disrupting vitals. If the bullet does not go through organs that are critical to an attackers immediate survival, it will not stop him or her. A deep penetrating bullet that zooms past vital structures without touching them is going to be as ineffective as a shallow penetrating bullet that stops a fraction of an inch short of passing through a vital structure. The rationale for the 12-inch minimum penetration guideline is simply to ensure the bullet has sufficient penetration potential to reach and disrupt vitals from any angle. Thats it!
Metcalfs "wound area" criteria is apparently based on the concept that, even though the bullet might disrupt non-vital vascular structures only, the resultant blood loss caused by the "wound surface area" is somehow going to matter. If the bullet doesnt pass through major blood distribution or processing organs, the wounds "surface area" is irrelevant to rapid incapacitation. If the bullet passes through the wall of the heart or a major blood vessel, the size of the hole produced will be a factor in the rate of blood loss, but that is a function of the bullets diameter and shape, not on "wound volume" or "wound surface area." Bleeding will be mostly internal, spilling directly into the abdominal cavity.
Good points about Metcalfs article include his practice of testing three samples of each cartridge. This provides a reasonable indication of terminal performance. We also agree with his choice to use "plain old-fashioned FMJ" if he "had to carry a .32 ACP" pocket pistol.
Despite its flaws, Metcalfs article is one of the better ammunition test reports weve encountered in a newsstand gun magazine. Its major shortcoming is the absence of gelatin calibration data. Had Metcalf included this vital information in his article, we could have reported to you whether or not his terminal performance results are credible or not.
Were hoping the day will come when we can write a positive review about newsstand gun magazine articles that report about ammunition performance testing. Critical reviews are neither pleasant to write nor publish, but we feel its our obligation to point out weaknesses that can affect your safety. Our purpose in reviewing these articles is to provide constructive criticism that will increase everyones knowledge about valid wound ballistics testing and reporting practices. We intend to mail a copy of this review to Mr. Metcalf and the editor of Shooting Times, and offer our assistance and advice for any future ammunition performance tests and reports.
- MacPherson, Duncan: "Corrections for JHP Bullets in Non-standard Gelatin," Bullet Penetration, Ballistic Publications, El Segundo, California, 1994; pp. 256-257.
- MacPherson, Duncan: "A Simplified Penetration Depth Correction for Data Taken in Non-standard Gelatin." Wound Ballistics Review 2(2), 1995; pp. 41-45.
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