More Lemas BS...

[DocGKR]

"I followed your links to order a copy of the report, however you have to be a contractor or "sponsored" in order to get access to this report. Any suggestions?"

FOIA.

[John_Wayne777]

I find the level of animus displayed on this subject surprising in a forum generally recognized for its professionalism.

Factual observations by professionals on either side of an issue ought to be treated with respect. Hyperbolic characterizations from both sides ought to be ignored.

With respect to the ammo, what it is and how it's made are facts that can be independently verified and are well known. What it does seems to be in some dispute as observed by professionals on both sides.

I think the tone and tenor of the discussion could be considerably improved.

There is a lot of history behind the LeMas thing that you might not be aware of. This blended metal thing has been going on for years and has involved some rather fantastic claims. Early on they actually claimed that the bullet could "sense" what sort of medium it was passing through and adjust its behavior accordingly.

Representatives of LeMas then proceeded to jump onto various forums and attack anybody who dared to question just how in heck a bullet could actually accomplish such a feat. This usually involved outright lies, half truths, belligerence, and even personal insults on their part.

The animus you see is a result of the extremely unprofessional behavior and piss-poor attitude those folks presented when their fantastic claims wouldn't stand up to any scrutiny or when experts pointed out that many of the Blended Metal Disciples were out of their lane.

[Littlelebowski]

I really don't see how anyone can argue the point after DocGKR's excellent analysis.

[Shawn Dodson]

Take some time and tell me what of the author's observations stated in the article are misinformation. Otherwise, I am as ignorant of the point you are trying to make as I was before I read your posts.

"Bob Pilgrim" writes (p48):
Here we now have small arms ammunitions that will “bust” 3A armor, penetrate hard barriers, but at the same time not slice through tissue and threaten the community we are sworn to protect.

If the ammo perforates body armor, it will also penetrate an officer's armor if an adversary obtains control of the officer's handgun - increasing danger to the officer, responding officers, and community. In addition, if this ammo is as deadly as depicted then it would seem that an officer's stray bullets would present greater danger to the community. (I understand these are not wound ballistics observations. I felt compelled to comment on the author's rationale.)

"Bob Pilgrim" writes (p48):
Although American ballisticians claim that 10-percent Kind and Knox ballistic gelatin simulates living tissue, none of the homogeneous test media currently in use accurately replicates living human tissue, because the latter is not consistent in its composition. Bone, cartilage, connective tissue and organs of varying densities will react differently to invasive, high velocity projectiles and produce different results in bullet penetration and deformation.

This is classic LeMas marketing disinformation, of which several more examples follow. Except for bone, the inconsistent composition of human soft tissues is irrelevant because the inhomogeneities are not significant enough to affect bullet performance. As described by Duncan MacPherson:

When a bullet is penetrating any material (tissue, water, air, wood, etc.), the total force the bullet exerts on the material is the same as the total force the material exerts on the bullet (this is Newton’s Third Law of Motion). These forces may be represented as a combination of shear forces and inertial forces (don’t be concerned if these words sound too technical – the concepts are easy). Shear force may be thought of as the force that resists deformation; if you push on a wall you are creating shear forces in the wall material that resist your push. If you push your hand down very slowly on a water surface, you feel no resisting force; this is true because a liquid cannot support a shear force….

You can fan your hand back and forth in air quite rapidly because there seems to be no resistance, but a similar fanning motion cannot be done nearly as rapidly underwater because moving the water can take all the strength you can muster. The forces that resist the movement of your hand in water are inertial forces….

A bullet penetrating a soft solid (tissue or a tissue simulant like gelatin) meets resistance that is a combination of shear forces and inertial forces….

…Anyone who has worked with gelatin knows that a finger can be pushed into gelatin with a force of only a few pounds; this force is similar to the resistance to a finger poked into the stomach, but the tissue does not fracture as easily as gelatin does. A finger poked into water does not meet this kind of resistance, which is due to shear forces. Penetration of a 9mm bullet at 1000 ft/sec is resisted by an inertial force of about 800 pounds; it is obvious that the presence or absence of a 3 to 5 pound shear force makes no practical difference in the penetration at this velocity. This also explains why the fact that gelatin fractures more easily than tissue does is not important.

The extension of these dynamics to soft tissue variation is obvious. Different types of tissue present different resistance to finger probing by a surgeon, but the surgeon is not probing at 1000 ft/sec. Different tissue types do have differences in the amount of shear force they will support, but all of these forces are so small relative to inertial forces that there is no practical difference. The tissue types are closer to one another than they are to water, and bullet expansion in water and tissue are nearly identical at velocities over 600 ft/sec where all bullet expansion takes place (See Bullet Penetration for a detailed explanation of bullet expansion dynamics).

Since inertial forces depend on accelerating mass, it makes sense that these forces should be lower at lower velocities (because the penetrated material cannot be accelerated to a velocity higher than the bullet). Shear forces have little velocity dependence, and as a result, shear forces are a much larger fraction of the total when bullet velocity is below the cavitation threshold. This low velocity effect is the reason that total bullet penetration depth is much different in water and in tissue or a valid tissue simulant.

As a result of the penetration dynamics, most soft solids with a density very near soft tissues (i.e., near the density of water) are satisfactory tissue simulants when shear forces are not important. However, total penetration depth depends significantly on dynamics at velocities below 400 ft/sec, so most materials do not properly simulate penetration depth. The total bullet penetration depth in tissue and a valid tissue simulant should be the same; standard practice is to use calibrated gelatin to insure this. In effect, gelatin calibration is done to ensure that the shear forces in the gelatin are the same as in typical soft tissue (as described in Bullet Penetration, the technical parameter used in the dynamic is viscosity).

Extract from “Wound Ballistics Misconceptions.” (Duncan MacPherson, Wound Ballistics Review, 2(3): 1996; 42-43)

Further, as reported by Fackler:

The test of the wound profiles’ validity [produced in properly prepared and calibrated ordnance gelatin] is how accurately they portray the projectile-tissue interaction observed in shots that penetrate the human body. Since most shots in the human body traverse various tissues, we would expect the wound profiles to vary somewhat, depending on the tissues traversed. However, the only radical departure has been found to occur when the projectile strikes bone: this predictably deforms the bullet more than soft tissue, reducing its overall penetration depth, and sometimes altering the angle of the projectile’s course. Shots traversing only soft tissues in humans have shown damage patterns of remarkably close approximation to the wound profiles.

The bullet penetration depth comparison, as well as the similarity in bullet deformation and yaw patterns, between human soft tissue and 10% ordnance gelatin have proven to be consistent and reliable. Every time there appeared to be an inconsistency…a good reason was found and when the exact circumstances were matched, the results matched. The cases reported here comprise but a small fraction of the documented comparisons which have established 10% ordnance gelatin as a valid tissue simulant.

Extracts from “The Wound Profile & The Human Body: Damage Pattern Correlation.” (Martin L Fackler, MD, Wound Ballistics Review, 1(4): 1994; 12-19)

I'll post another reply tomorrow. sd

[QuietShootr]

Article from American Cop Magazine about Lemas Ammo

Holy ****, this shit won't die. Bulmer must be having trouble getting gigs.

[QuietShootr]

I know the man referred to as "Bob Pilgrim"--under his true name, he is a well respected retired FBI agent with an extensive background in CQB.

Yet again, this proves what I've said all along - "Certified Bad Ass" creds do NOT mean someone knows their ass from their elbows about anything outside what they had a specific block of instruction on.

[Zhukov]

<snip>

You still alive, you crotchety old goat?

[QuietShootr]

You still alive, you crotchety old goat?

For now, you square-headed Prussian :-) They'll get me eventually. Today just wasn't the day.

Text me sometime, dude!

[Shawn Dodson]

I was planning to do a point by point critique of the AmCop article but in the end I decided to address it in general terms.

In regard to the LeMas bullets “deploying” (LeMas terminology for bullet upset) in only warm test media (flesh/Perma Gel), and in “live tissue,” I believe we need to consider Dr. Fackler’s observation in regard to differences in terminal performance observed between actual shootings as compared to ordnance gelatin:

"Every time there appeared to be an inconsistency…a good reason was found and when the exact circumstances were matched, the results matched."

-- Dr. Fackler

The article by “Bob Pilgrim” reports that shots were made into swine thorax and extremities. Apparently no abdominal shots were performed. I speculate the LeMas bullets require substantial shear force (explained by MacPherson in my earlier post) to cause the bullet to deform then fragment. Bone and connective tissues (e.g., tough membrane lining the ribcage) may provide the necessary resistance to make the LeMas bullet “deploy”.

If this is true then LeMas bullet performance is unpredictable because it is dependent on the kind of tissues it encounters (versus being “tissue blind”). Shots to the abdomen might not produce bullet upset, which is why I conjecture that no abdominal shots were attempted during the tests observed by “Bob Pilgrim.”

I don’t know anything about Perma Gel as I have never worked with it, thus I don’t know its properties. As reported in the article, LeMas bullets “deployed” in warm Perma Gel (85 degrees ambient, exposed to full sunlight) but not in cool Perma Gel (65 degrees ambient). Again we must fall back on Fackler’s observation when differences in terminal performance are detected.

But how much time is the bullet exposed to a warm media before it “deploys”? Looking at LeMas bullet velocities reported in the article I decided to use 2000 fps as a reference velocity to determine time of impact to time of “deployment”. If the distance traveled is 2-inches (~4 bullet lengths), then a “temperature sensitive bullet” must detect and react to a warm temperature in 83 microseconds (42 microseconds for 1-inch penetration, or ~2 bullet lengths). Duncan MacPherson described that the bullet is exposed to body heat for less time than the time it takes for you to pass your finger quickly through a candle flame. Because of the extremely short exposure time you don’t sense the heat (and neither does the bullet).

More interesting to me though, in light of claims of temperature sensitivity, is how LeMas bullets perform after being exposed to the heat and sunlight of a hot Florida day. Will a warmed bullet be less sensitive to temperature? What affect would cold/cool temperatures have on terminal performance? (Rhetorical questions both.)

Quite honestly, given the many outlandish claims that have been investigated and discredited by reputable researchers, it’s unlikely that any further time and effort is going to be spent independently investigating LeMas’ extraordinary claims.

Maybe the author of the article might become skeptical and investigate for himself the validity of LeMas claims (find out a good reason why LeMas ammo allegedly performs differently) instead of blindly accepting information that has been spoon fed to him and witnessing test events (that could be rigged) without question?

Finally, it would seem wise for a law enforcement agency to consider the political, legal and moral significance of issuing pistol ammunition that is practically advertised as producing such severe wound trauma that a person shot by it is almost 100 percent certain to die. (Think of Al Sharpton & Jesse Jackson, for example, stirring up community outrage.) It could be argued, given the claims by LeMas and reports by "Bob Pilgrim”, that instead of shooting to stop law enforcement personnel are now shooting to kill. It can’t happen?! Consider the Winchester Black Talon (“Black Felon”) debacle. sd

[HowardCohodas]

Shawn,

Your references and quotes in your earlier post were worth while and gave me interesting study material. I appreciate it.

Your next post disappoints me. I want to consider you seriously, but your speculation to facts ratio was so far out of my personal bounds in a post meant to convey fact that it concerns me greatly. I can speculate fine. Your pedagogy would be more helpful if it were directed toward analysis.