Hornady Critical Duty and Critical Defense. What's the Difference?

[spyderco monkey]

Which of the above quotes are from people who are contracted to do, small arms, ammunition development, and testing?

None of those.

The closest to study the TSC 'rifle zone threshold' is Brassfetcher in this paper here:

https://brassfetcher.com/Wounding%20...Expansion.html

Temporary Cavity Velocity and Diameter of Representative Handgun and Rifle Cartridges in 20% Ballistic Gelatin

Pistol cartridges including .22LR, .32ACP, .380ACP, 9x19mm, .40S&W, .45ACP, .357 Magnum, .44 Magnum JHPs as well as 22 K-Hornet, 223 Remington, 260 Remington, 308 Winchester and 30-06 Springfield rifles were evaluated in 20-percent ballistic gelatin and the results recorded on high speed video. From these videos, analysis was conducted of the velocity and instantaneous kinetic energy of the point of maximum temporary cavity diameter for each shot.

It was found that the magnitude of kinetic energy present at any point during the expansion was directly attributable to the initial velocity of the projectile at impact. Expanded diameter appeared to play little, if any role in influencing temporary cavity diameter. Handguns such as 9x19mm and .40S&W appear to be the lower threshold for wounding through tissue expansion, with .357 Magnum a marked improvement over the two. Rifles of moderate recoil demonstrate impressive tissue expansion upon bullet impact.

In view of quantifying any potential wounding effects of the temporary cavity expansion, the kinetic energy of the cavity was measured by assuming the analyzed segment of the track to be a disc with a uniform diameter corresponding to the measured temporary cavity diameter at a given time and a thickness of 0.10” inch. Using the density of 20-percent ballistic gelatin, a weight for the given compressed section was determined and thus, the kinetic energy was calculated from the mass of this section and the instantaneous measured velocity. Being constrained on this report to work within the (very limited) publicly-available data set for human survivability, we set the upper limit of non-injury to be that of the kinetic energy corresponding to a commercial BB gun at 430 ft/sec. Hits with this weapon are not generally associated with fatal wounds, so should provide a somewhat realistic representation of what could be expected to happen to unprotected internal organs being stressed by an equivalent force.)"

Whole article is worth perusing. But supporting the decades of anecdotes about the 125gr .357 being 'different' then .380-9mm-.40-.45, his testing shows a much higher level of energy in the TSC then those standard pistol calibers, which are all pretty similar to one another.

"With a peak radial kinetic energy of 1.25 ft-lbf, the .380ACP 90gr Speer Gold Dot JHP is not capable of creating damage outside of the tissue that it directly crushes.

With a peak radial kinetic energy of 1.96 ft-lbf, the 9x19mm 124gr Remington +P Golden Saber JHP is not capable of creating damage outside of the tissue that it directly crushes.

With a peak radial kinetic energy of 0.55 ft-lbf, the 9x19mm 147gr Remington Golden Saber JHP is not capable of creating damage outside of the tissue that it directly crushes.

With a peak radial kinetic energy of 7.85 ft-lbf, the radial movement of tissue away from a 357 Magnum 125gr Speer Gold Dot JHP (at 1405 ft/sec impact velocity) is capable of creating a wound similar to a 0.177” steel BB traveling at 850 ft/sec. At that velocity, a steel BB is capable of penetrating well over 4” of 10-percent ballistic gelatin.

With a peak radial kinetic energy of 2.29 ft-lbf, the radial movement of tissue away from a 40S&W 180gr Speer Gold Dot Short Barrel (at 970 ft/sec impact velocity) is capable of creating a wound similar to a 0.177” steel BB traveling at 459 ft/sec. This is a kinetic energy sufficiently high to disable an organ with ballistic resistance similar to a human eye.

With a peak radial kinetic energy of 2.26 ft-lbf, the radial movement of tissue away from a 45ACP 185gr Remington +P Golden Saber (at 1024 ft/sec impact velocity) is capable of creating a wound similar to a 0.177” steel BB traveling at 456 ft/sec. This is a kinetic energy sufficiently high to disable an organ with ballistic resistance similar to a human eye.

With a peak radial kinetic energy of 1.28 ft-lbf, the 45ACP 230gr Remington Golden Saber JHP (impacting at 817 ft/sec) is not capable of creating damage outside of the tissue that it directly crushes."

[wolf76]

None of those.

The closest to study the TSC 'rifle zone threshold' is Brassfetcher in this paper here:

https://brassfetcher.com/Wounding%20...Expansion.html

Temporary Cavity Velocity and Diameter of Representative Handgun and Rifle Cartridges in 20% Ballistic Gelatin

Pistol cartridges including .22LR, .32ACP, .380ACP, 9x19mm, .40S&W, .45ACP, .357 Magnum, .44 Magnum JHPs as well as 22 K-Hornet, 223 Remington, 260 Remington, 308 Winchester and 30-06 Springfield rifles were evaluated in 20-percent ballistic gelatin and the results recorded on high speed video. From these videos, analysis was conducted of the velocity and instantaneous kinetic energy of the point of maximum temporary cavity diameter for each shot.

It was found that the magnitude of kinetic energy present at any point during the expansion was directly attributable to the initial velocity of the projectile at impact. Expanded diameter appeared to play little, if any role in influencing temporary cavity diameter. Handguns such as 9x19mm and .40S&W appear to be the lower threshold for wounding through tissue expansion, with .357 Magnum a marked improvement over the two. Rifles of moderate recoil demonstrate impressive tissue expansion upon bullet impact.

In view of quantifying any potential wounding effects of the temporary cavity expansion, the kinetic energy of the cavity was measured by assuming the analyzed segment of the track to be a disc with a uniform diameter corresponding to the measured temporary cavity diameter at a given time and a thickness of 0.10” inch. Using the density of 20-percent ballistic gelatin, a weight for the given compressed section was determined and thus, the kinetic energy was calculated from the mass of this section and the instantaneous measured velocity. Being constrained on this report to work within the (very limited) publicly-available data set for human survivability, we set the upper limit of non-injury to be that of the kinetic energy corresponding to a commercial BB gun at 430 ft/sec. Hits with this weapon are not generally associated with fatal wounds, so should provide a somewhat realistic representation of what could be expected to happen to unprotected internal organs being stressed by an equivalent force.)"

Whole article is worth perusing. But supporting the decades of anecdotes about the 125gr .357 being 'different' then .380-9mm-.40-.45, his testing shows a much higher level of energy in the TSC then those standard pistol calibers, which are all pretty similar to one another.

"With a peak radial kinetic energy of 1.25 ft-lbf, the .380ACP 90gr Speer Gold Dot JHP is not capable of creating damage outside of the tissue that it directly crushes.

With a peak radial kinetic energy of 1.96 ft-lbf, the 9x19mm 124gr Remington +P Golden Saber JHP is not capable of creating damage outside of the tissue that it directly crushes.

With a peak radial kinetic energy of 0.55 ft-lbf, the 9x19mm 147gr Remington Golden Saber JHP is not capable of creating damage outside of the tissue that it directly crushes.

With a peak radial kinetic energy of 7.85 ft-lbf, the radial movement of tissue away from a 357 Magnum 125gr Speer Gold Dot JHP (at 1405 ft/sec impact velocity) is capable of creating a wound similar to a 0.177” steel BB traveling at 850 ft/sec. At that velocity, a steel BB is capable of penetrating well over 4” of 10-percent ballistic gelatin.

With a peak radial kinetic energy of 2.29 ft-lbf, the radial movement of tissue away from a 40S&W 180gr Speer Gold Dot Short Barrel (at 970 ft/sec impact velocity) is capable of creating a wound similar to a 0.177” steel BB traveling at 459 ft/sec. This is a kinetic energy sufficiently high to disable an organ with ballistic resistance similar to a human eye.

With a peak radial kinetic energy of 2.26 ft-lbf, the radial movement of tissue away from a 45ACP 185gr Remington +P Golden Saber (at 1024 ft/sec impact velocity) is capable of creating a wound similar to a 0.177” steel BB traveling at 456 ft/sec. This is a kinetic energy sufficiently high to disable an organ with ballistic resistance similar to a human eye.

With a peak radial kinetic energy of 1.28 ft-lbf, the 45ACP 230gr Remington Golden Saber JHP (impacting at 817 ft/sec) is not capable of creating damage outside of the tissue that it directly crushes."

AFAIK, Brassfetcher's paper does not prove/imply that .357 magnum would produce significant damage in elastic tissue via the synergistic effects of bullet fragmentation and a large temporary cavity, which was your assumption about the .357 magnum 125 gr JHP.

If you believe that .357 magnum produces substantial temporary cavity stretch that would contribute significantly to wounding, then please provide measurements of the max fracture profile for properly conducted static gel tests using appropriately sized and calibrated 10% gelatin blocks.

The scientific testing done by wound ballistics SMEs, like Dr. Fackler and DocGKR, contradicts the anectodal accounts from your earlier posts about .357 magnum and .357 SIG being magic bullets. From everything that I have read from these ballistics SMEs, certain .44 magnum loads and .30 carbine JSP produce temporary cavities that are beginning to be a significant wounding mechanism but .357 magnum is not in that transitional range.

Post #4 by DocGKR in this thread makes it pretty clear that .357" magnum does not produce wounds similar to a fragmenting rifle round and that the temporary cavity produced by .357 magnum is still too small to be a significant wounding factor: https://www.mp-pistol.com/threads/do...uestion.11919/

[Ed L]

Elsewhere @DocGKR wrote:

"Not all LE agencies found the .357 Mag 125 gr JHP to be that great. The CHP documented the greatly improved terminal effectiveness of the .40 S&W Winchester 180 gr JHP (ave MV of 949 f/s from the 4" barrel of their S&W 4006 pistols) compared to the previously issued .357 Mag Remington 125 gr JHP (ave MV of 1450 f/s from their 4" S&W duty revolvers)."

[Hambo]

IMO probably before Miami there was no measurement of what was considered to be "enough".

I don't think it's just your opinion. Silvertips weren't any worse than anything else at the time. Everything that came out after Miami was not better. Eventually we got to the current era of really good, really consistent, JHPs.

[spyderco monkey]

AFAIK, Brassfetcher's paper does not prove/imply that .357 magnum would produce significant damage in elastic tissue via the synergistic effects of bullet fragmentation and a large temporary cavity, which was your assumption about the .357 magnum 125 gr JHP.

If you believe that .357 magnum produces substantial temporary cavity stretch that would contribute significantly to wounding, then please provide measurements of the max fracture profile for properly conducted static gel tests using appropriately sized and calibrated 10% gelatin blocks.

As I said earlier, it's a hypothesis of mine (a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation). I'm not putting it forward as fact. But based on decades of pretty consistent anecdotal reports, plus now this Brassfetcher report, and the fact that a 125gr @ 1450 has nearly identical energy to the supposed rifle threshold 55gr @ 2200fps, I still wonder if there's more 'there there' than what we currently understand.

More broadly I'd like to see a study that pins down where the pistol effects (hole poking) to rifle effects (hole poking + TSC damage) transition zone is, and what causes it.

Is it purely velocity? Is it energy? Energy + rate of energy loss? Velocity + Energy + Rate of Energy loss? Is it TSC ft/lbs of energy as Brassfetcher suggests, and if so, how many TSC ftlbs are needed to enter this transition zone?

This applies in both directions. One, to see if it is possible to design a practical autoloading cartridge and projectile that is able to reach this transition zone. But two, to also evaluate at what range a rifle will drop out of 'rifle zone' effectiveness and into pistol zone hole poking.

Has such a study been conducted?

[Velo Dog]

Has such a study been conducted?

I find the experience of hunters very interesting.

https://www.ballisticstudies.com/Kno...57+Magnum.html

"As a general guide to performance, the .357 can produce quite spectacular kills at impact velocities of 2000fps and faster using hollow point projectiles.

At impact velocities of 2000 to 1600fps, game hit with a fast expanding hollow point tend to react in a drunken manner, often attempting to run but not generally making too much ground before succumbing quickly to blood loss.

Between 1600 and 1300fps, dead runs may be longer but wounding is still somewhat disproportionate to caliber. Again, bullet weights must be matched to the job at hand. If the bullet is too heavy, it may not meet enough resistance to render a wide wound at low velocities. If the bullet is too light, it may not have enough energy to render a deep and broad wound on larger bodied animals.

At impact velocities of 1200fps and below, bullet expansion may be fully evident, yet wounding can be narrow (proportionate to the expanded caliber of the bullet) and blood trails poor. At these velocities and in the absence of any major hydraulic force, the .357 is reliant on mechanical wounding, the size of the wound being directly proportionate to the diameter of the expanded bullet."

[mmc45414]

I don't think it's just your opinion. Silvertips weren't any worse than anything else at the time. Everything that came out after Miami was not better. Eventually we got to the current era of really good, really consistent, JHPs.

Seems like it was all about expansion, and not so much about penetration.

[DocGKR]

Projectile designs in the 1970's and early 1980's were about maximizing RII.

The Relative Incapacitation Index (RII) developed by the National Institute of Justice Law Enforcement Assistance Administration in 1973, was an attempt to determine which handgun bullets would have the greatest wounding effect and would incapacitate a human most reliably. Using a overly simplistic “computer man” model of human anatomy, RII erroneously assumed that the size of the temporary cavity produced by a given handgun bullet in ordnance gelatin is directly proportional to the wounding effect and incapacitation produced by that bullet in a human. The study recommended lightweight, high velocity bullets with rapid expansion in tissue and frangible, pre-fragmented bullets, such as the Glaser Safety Slug, as producing the greatest wounding effect and most reliable incapacitation in humans. The RII completely ignored the size and depth of the permanent cavity, the tissue which is actually destroyed by the bullet. Since many tissues in the human body are elastic, they absorb the stretch and tissue displacement produced by temporary cavitation with minimal damage.

Lightweight, high velocity handgun bullets which rapidly expand in tissue have decreased penetration depth compared to heavier, slower, less deformed bullets and cannot consistently reach the major organs and blood vessels in the torso, especially from transverse and oblique angles. Frangible handgun bullets designed to fragment on impact, like the Glaser and MagSafe, produce large shallow wounds, have extremely limited tissue penetration depth, and cannot consistently reach the major organs and blood vessels in the torso, especially from transverse and oblique angles. In addition, they cannot defeat commonly encountered intermediate obstacles.

Shallow penetrating, lightweight, high velocity, rapidly expanding bullets and frangible, pre-fragmented bullets were recommended because of the widespread fear of handgun bullet over-penetration, in other words, a bullet which completely passes through the body, exits the other side, and continues on to potentially endanger innocent bystanders. This feared hazard has been greatly exaggerated. The skin on the exit side of the body is tough, resilient, and flexible, and can have the same resistance to bullet passage as four inches (10 cm) of muscle. This often results in bullets ending their path just under the skin at the anticipated exit point rather than over-penetrating as might be expected. In addition, those few bullets which over-penetrate after hitting the target are not any more dangerous to innocent bystanders than the overwhelming majority of bullets fired by law enforcement personnel which miss the intended target all together.

According to Special Agent Urey Patrick, formerly Assistant Chief of the FBI Firearms Training Unit:

"Choosing a bullet because of relatively shallow penetration will seriously compromise weapon effectiveness and needlessly endanger the lives of law enforcement officers using it. No law enforcement officer has lost his life because a bullet over-penetrated his adversary, and virtually none has ever been sued for hitting an innocent bystander through an adversary. On the other hand, tragically large numbers of officers have been killed because their bullets did not penetrate deeply enough."

The RII was seriously flawed and its recommendations erroneous. Deeper penetrating bullets have proven to be far superior to shallow penetrating bullets in LE OIS incidents since they have sufficient penetration to consistently reach the major organs and blood vessels in the torso, even from transverse and oblique angles and through intermediate obstacles.

[DocGKR]

Have folks who should know better (ie. professional law enforcement, military, forensic, and medical personnel) forgotten their history???

The old adage from Winston Churchill comes to mind: "Those that fail to learn from history are doomed to repeat it.”

Y'all might want to review this: https://pistol-forum.com/showthread....in-water/page2

[willie]

I've noticed an increased interest in .22, 32 ACP, and 380 ACP handguns for self defense use. I think that a safe statement is that civilians are more likely to select them. I have high regard for my older Ruger LCP. However, sometimes I wonder how many 380 bullets would be required to stop an attacker, and would I get my ass beat after I ran out of bullets?