4LD Test

[94045]

I have a new round that I'm trying.
Through 4LD (4-Layers of Denim) and hog hide I'm getting minimal expansion and about 4-6" to much penetration. Through 2LD and hog hide I'm getting penetration within the high end of the range and average expansion. Through 2TS (2-Layers T-Shirt) and hog hide I'm getting above average expansion and average penetration.

I live in the Southern USA. How much weight should I give to the 4LD results. Should I try FBI Heavy Clothing protocol instead?

PS the hog hide is a given since the test media is a dead wild hog.

 

[tarosean]

I live in the Southern USA. How much weight should I give to the 4LD results. Should I try FBI Heavy Clothing protocol instead?

I live in the Gulf Coast TX where aside from a couple weeks a year. The likely hood of running into someone wearing multiple layers of anything is going to be extremely low.

If I lived/worked somewhere where heavy clothing was worn for many months at a time I might be interested in those type of tests. my 2 cents.

 

[Waveski]

Who wears 4 layers of denim, north or south ?
Seems like and odd test set up, 4 layers of stout material , each one deflecting on impact and absorbing energy.

 

[tarosean]

Who wears 4 layers of denim, north or south

Heck I dont think I've seen a person wearing a Jean Jacket in about 20yrs..

 

[Hartkopf]

I don't worry about the 4 layers of denim results. I regularly get good (great) ammo that completely clogs with 4LD, but is great with 2LD+Tshirt.

In heavy winter clothing there's a good chance, IMHO that every handgun ammo will clog and you get FMJ results. 4LD not a concern in Texas for me.

 

[sequins]

This is why I like 45. Expanding 9mm has to work just right to get FMJ results from 45. The 45 floor is the 9mm ceiling.

 

[Dunross]

It's the hog hide that is throwing off your test in my opinion. Though FOUR layers of denim is not a good test either, I believe.

Unless you were to shoot them in the crotch in the winter time. Maybe then someone would be wearing four layers of denim!

 

[Waveski]

Nobody wears 4 layers of denim on their crotch , or anywhere else. 2 layers where pants and coat overlap , that’s it. Sweater under the coat , flannel lining -sure. 4LD?
Never.

 

[redneck]

38 degrees and pouring down rain today in Ohio. I did the barn work wearing, a carhart vest, over a duluth firehose shirt jacket, over carhart bibs, over a redhead brand denim work shirt...I don't know what the meth heads are wearing these days but the farmers, ranchers and construction workers pretty much have on 4 layers of denim

 

[fastbolt]

It's not unusual for some folks to think that the use of 4 layers of 14oz denim is supposed to represent a hypothetical person actually wearing that many layers of denim clothing. That's not what it represents.

Some reading invested into the reasons for the development of both the FBI's ammunition testing protocols for duty ammunition, and the reasoning for the additional development of the 4LD/organic gel testing (not part of the FBI testing protocols, BTW), might offer some better insights into the use of the various test medium materials in the scientific testing scenarios.

One of the interesting things about the 4LD testing was that the bullets that were able to reliably expand in the test were also found to have exhibited similar expansion in actual shooting incidents. Think of it as an engineering 'acid test' for a JHP design that can demonstrate the potential to resist plugging and yet also exhibit robust expansion.

The use of hog hide as an additional barrier medium, or any additional material that changes the any of the testing conditions, means you've stepped off into uncharted territory as far as being able to compare the results to the established scientific testing protocols.

The use of carefully prepared 10% organic gel blocks, maintained at a specific temperature range (and 'calibrated' via specific velocity BB gun test shot measurement), aren't easy for backyard and hobbyist testing, granted. The water-filled bags used for a "Fackler Box" can also yield some results, following the right formula for understanding the relevance of the resulting 'penetration'.

Once the 'informal testing' veers outside of the carefully created scientific testing methods, using specific materials (so results are consistent and reproducible), it's anybody's guess. Might as well go back to shooting water-soaked phone books or newsprint, modeling clay, duxseal, water bottles or canned food, etc. The yardstick is no longer exactly consistent.

 

[94045]

It's not unusual for some folks to think that the use of 4 layers of 14oz denim is supposed to represent a hypothetical person actually wearing that many layers of denim clothing. That's not what it represents.

Some reading invested into the reasons for the development of both the FBI's ammunition testing protocols for duty ammunition, and the reasoning for the additional development of the 4LD/organic gel testing (not part of the FBI testing protocols, BTW), might offer some better insights into the use of the various test medium materials in the scientific testing scenarios.

One of the interesting things about the 4LD testing was that the bullets that were able to reliably expand in the test were also found to have exhibited similar expansion in actual shooting incidents. Think of it as an engineering 'acid test' for a JHP design that can demonstrate the potential to resist plugging and yet also exhibit robust expansion.

The use of hog hide as an additional barrier medium, or any additional material that changes the any of the testing conditions, means you've stepped off into uncharted territory as far as being able to compare the results to the established scientific testing protocols.

The use of carefully prepared 10% organic gel blocks, maintained at a specific temperature range (and 'calibrated' via specific velocity BB gun test shot measurement), aren't easy for backyard and hobbyist testing, granted. The water-filled bags used for a "Fackler Box" can also yield some results, following the right formula for understanding the relevance of the resulting 'penetration'.

Once the 'informal testing' veers outside of the carefully created scientific testing methods, using specific materials (so results are consistent and reproducible), it's anybody's guess. Might as well go back to shooting water-soaked phone books or newsprint, modeling clay, duxseal, water bottles or canned food, etc. The yardstick is no longer exactly consistent.

The information I've seen says 10% Ordnance Gel is representative of projectiles that penetrate soft tissue only and don't exit the body and within those parameters has an expected error rate of up to 20%.

I do agree that wild hogs as a general rule have a more robust structure and the hide is thicker so projectiles that under penetrate in this environment may not in their intended environment.

I think 2LD and the Hide may be more representative of the 4LD test based on past performance. I've had more than one highly regarded bullet fail when subjected to 4LD and hide. I think in the future I may use a Windbreaker, Hoody and T-Shirt Combo as more representative. It should should still be tougher with the hide.

To say this is an unresearched mode of testing is a bit disingenuous. See - The International Journal of Legal Medicine "Comparison of porcine thorax to gelatine blocks for wound ballistics studies". Admittedly they were using simulated thorax and domestic hog tissue without hide.

 

[Waveski]

38 degrees and pouring down rain today in Ohio. I did the barn work wearing, a carhart vest, over a duluth firehose shirt jacket, over carhart bibs, over a redhead brand denim work shirt...I don't know what the meth heads are wearing these days but the farmers, ranchers and construction workers pretty much have on 4 layers of denim

There you have it folks , I stand corrected.
Heavy denim layers prevail in settings where good folks work hard to make an honest living.

 

[fastbolt]

The organic gel formula used for modern handgun ballistic testing (10%) was developed to simulate swine (porcine) muscle tissue, not bone or hide. If you want to vary the test medium methods, don't be surprised if the results vary from those produced when other mediums and protocols are used.

Dr Martin Fackler developed and refined this testing medium when he was the head (and founder) of the Wound Ballistics Laboratory for the Letterman Army Institute of Research. Even carefully mixed, maintained at the proper temperature and 'calibrated' (penetration of BB fired at specific velocity), it wasn't promoted or guaranteed to be an exact model of the obviously non-homogeneous human anatomy, but was designed to roughly approximate swine muscle tissue (thought to be similar to human muscle tissue).

If test protocols and materials are substantively changed, expect potentially different 'results'.

Even when the FBI was working with surgeons and other medical professionals during the development of their own gel testing protocols, the SSA writing their original in-house paper on wound ballistics recognized the importance of looking at both lab results and reports from actual shooting incidents, and didn't consider the results of lab gel testing to be the exclusive or definitive answer to wound ballistics questions. Testing methods for examine potential new duty ammunition, yes, but not something to answer all questions involving wound ballistics.

Gel testing can help you observe what a bullet may do when observed within the specific protocols of the lab testing (or, what the medium may do to the JHP bullet under similar conditions).

Now, when the 4LD denim/gel testing was later conceived and designed (not part of the FBI protocol), it was subsequently observed there was a correlation between recovered lab test JHP's and some JHP's fired in actual OIS incidents. No guarantees. No promises.

Also, the way a JHP bullet is acted upon by the medium into which it's fired doesn't exactly let someone 'predict' how a live organism (human or animal) may react when experiencing the GSW.

If you want to use your own informal testing methods and materials, you're basically on your own. Just like in earlier decades.

 

[94045]

The organic gel formula used for modern handgun ballistic testing (10%) was developed to simulate swine (porcine) muscle tissue, not bone or hide. If you want to vary the test medium methods, don't be surprised if the results vary from those produced when other mediums and protocols are used.

Dr Martin Fackler developed and refined this testing medium when he was the head (and founder) of the Wound Ballistics Laboratory for the Letterman Army Institute of Research. Even carefully mixed, maintained at the proper temperature and 'calibrated' (penetration of BB fired at specific velocity), it wasn't promoted or guaranteed to be an exact model of the obviously non-homogeneous human anatomy, but was designed to roughly approximate swine muscle tissue (thought to be similar to human muscle tissue).

If test protocols and materials are substantively changed, expect potentially different 'results'.

Even when the FBI was working with surgeons and other medical professionals during the development of their own gel testing protocols, the SSA writing their original in-house paper on wound ballistics recognized the importance of looking at both lab results and reports from actual shooting incidents, and didn't consider the results of lab gel testing to be the exclusive or definitive answer to wound ballistics questions. Testing methods for examine potential new duty ammunition, yes, but not something to answer all questions involving wound ballistics.

Gel testing can help you observe what a bullet may do when observed within the specific protocols of the lab testing (or, what the medium may do to the JHP bullet under similar conditions).

Now, when the 4LD denim/gel testing was later conceived and designed (not part of the FBI protocol), it was subsequently observed there was a correlation between recovered lab test JHP's and some JHP's fired in actual OIS incidents. No guarantees. No promises.

Also, the way a JHP bullet is acted upon by the medium into which it's fired doesn't exactly let someone 'predict' how a live organism (human or animal) may react when experiencing the GSW.

If you want to use your own informal testing methods and materials, you're basically on your own. Just like in earlier decades.

10% Gel replicates swine muscle tissue so don't use swine muscle tissue as it's not representative.

4LD is a worse case expansion test and not representative. Don't use hog hide as it could be a tougher test and we don't want a tougher test as it isn't representative.

Swine bodies shouldn't be used because while they may represent the intended target they are not straight muscle tissue and wouldn't replicate results well for bullets intended for use against 10% ordanace gel.

Did I understand the arguments correctly?

 

[bdickens]

10% ballistic gelatin doesn't replicate porcine tissue, it models an average of it. The difference is not merely semantic.

The tissue in a body (human or otherwise) is not homogeneous and therefore presents an obstacle to consistent test results. In other words, every shot is different so you can't compare them directly.

It so happens that swine and human tissue are remarkably similar.

 

[94045]

10% ballistic gelatin doesn't replicate porcine tissue, it models an average of it. The difference is not merely semantic.

The tissue in a body (human or otherwise) is not homogeneous and therefore presents an obstacle to consistent test results. In other words, every shot is different so you can't compare them directly.

It so happens that swine and human tissue are remarkably similar.

I'm not going looking at the links but several statements I've seen says it replicates porcine muscle tissue.

Regardless autopsy results I've seen seems to lead to the conclusion that it most closely simulates soft tissue +/- 20%.

Also the one thing I have learned is rib hits don't make lot of difference in penetration depth. Petals get pushed back or shear off and that tends to offset any momentum lost. In an appropriately sized pig I generally find the bullet under the hide or against the first layer of my bullet stop (fleece).

As long as it expands and penetrates a hog (with a clothing barrier) I am.more comfortable. I know variation in the test media is a given but when 5 out 5 of one lot expand and 5 out of 5 of the next doesn't I'm not as certain of the QC as some of you seem to be.

 

[fastbolt]

10% Gel replicates swine muscle tissue so don't use swine muscle tissue as it's not representative.

4LD is a worse case expansion test and not representative. Don't use hog hide as it could be a tougher test and we don't want a tougher test as it isn't representative.

Swine bodies shouldn't be used because while they may represent the intended target they are not straight muscle tissue and wouldn't replicate results well for bullets intended for use against 10% ordanace gel.

Did I understand the arguments correctly?

Nope.

I suspect you understood them in the manner you wished.

 

[bdickens]

Also the one thing I have learned is rib hits don't make lot of difference in penetration depth. Petals get pushed back or shear off and that tends to offset any momentum lost....

That is noteworthy and, I think, important to consider in light of where we tend to aim in SD and the objection many have to a gel block's "lack of bones."

As long as it expands and penetrates a hog (with a clothing barrier) I am.more comfortable. I know variation in the test media is a given but when 5 out 5 of one lot expand and 5 out of 5 of the next doesn't I'm not as certain of the QC as some of you seem to be.

Clarify please. Is the inconsistent expansion found in a hog or in ordnance gel?

 

[94045]

One lot # will expand 5 out of 5 times.
Next lot # will fail 5 out of 5 times.
Yes, it's in a hog carcass but it doesn't give me a warm fuzzy feeling when different lots perform very differently in a medium that I still believe is more representative than ordnance gel (not consistent like gel but inconsistent like the intended target). I don't use the lots that I can't get to expand. I'm not going to name brand names because this is not unique to any one brand. I guess I need to get some ordnance gel because it would be interesting to see if rounds that will not expand in a (porcine) body will in gel.

I'm sure you will say that the fact it won't expand in a (porcine) body doesn't matter only that it expand in gel.

 

[fastbolt]

There's always the possibility of QC issues involved in a bullet's manufacture (including dulling cutters, skiving/notching cut variability, etc) to potentially affect bullet upset, deformation and expansion. The manufacturers do their best when it comes to QC procedures, but when you're producing (or acquiring) massive numbers of components, it's unsurprising that some things might occasionally slip through automated or human visual inspections.

Once you look outside a lab, where shooting events 'occur in the wild' (so to speak), there's little wonder why many people who study the field of wound ballistics tend to refer to shooting events as being virtually unique regarding how humans and animals may react to GSW's in any particular incident.

Now, animal hide (whether with fur, course bristles, etc) is different among animals, let alone different from that of human skin layers. Muscle tissue underneath the layers of dermis? Bony structures and bone densities?

If someone were looking to maximize potential 'performance' for hunting hogs, then observing what happens when different ammunition is used to hunt hogs would probably be helpful.

 

[kBob]

Bottom seam of levis jacket = two layers, Fly of jeans = two layers together over groin equal four layers.

I wear a denim jacket in the cooler months, sometimes over my overalls

In even the hottest months I wear a t shirt under my outer shirt....even polo shirts.

Don't hardly ever say never!

Inland Florida is not noticeably less humid and hot in summer than Texas......

Sounds like interesting tests.

-kBob

 

[bdickens]

...several statements I've seen says it [ballistic gelatin] replicates porcine muscle tissue.

I generally dislike pedantry but in science it is extremely important to use language correctly which means using words according to their exact, precise scientific definitions.

To "replicate" means to produce an exact copy whereas to "model" is more along the lines of producing a simplified representation.

When people say that ballistic gelatin duplicates or replicates porcine tissue, they are technically incorrect. So, when others object and say "no it doesn't, because X, Y and Z," they are right.

However, both are missing the point. I believe because of confusion brought about by the imprecise use of language.

I realize that many of you will say I am being pedantic and overly technical here. But this is science and in science things like this really do matter.

 

[Robbins290]

Heck I dont think I've seen a person wearing a Jean Jacket in about 20yrs..

come to Maine, you will see that, ALOT.

 

[bdickens]

One lot # will expand 5 out of 5 times.
Next lot # will fail 5 out of 5 times.
Yes, it's in a hog carcass but it doesn't give me a warm fuzzy feeling when different lots perform very differently in a medium that I still believe is more representative than ordnance gel

Got it.

I guess I need to get some ordnance gel because it would be interesting to see if rounds that will not expand in a (porcine) body will in gel.

Yes. That would certainly be great to compare. Similar inconsistencies in both gel and hog carcasses I believe would rule the ammunition in question to be unreliable.

Inconsistent results in the hogs and consistent ones in the gel would give cause for concern and require further investigation.

Who knows? The explanation could be as simple as "shooting into an actual body is a crap shoot."

I'm sure you will say that the fact it won't expand in a (porcine) body doesn't matter only that it expand in gel.

Please don't misunderstand me. I'm the guy in the middle who believes that we should look at both the case studies and gel tests and correlate the findings of each as much as possible.

 

[Hartkopf]

There's always the possibility of QC issues involved in a bullet's manufacture (including dulling cutters, skiving/notching cut variability, etc) to potentially affect bullet upset, deformation and expansion. The manufacturers do their best when it comes to QC procedures, but when you're producing (or acquiring) massive numbers of components, it's unsurprising that some things might occasionally slip through automated or human visual inspections.

You clearly understand the limitations of modern manufacturing! There are some that would argue the only possible cause of 94045’s test it that his test is flawed. His test could have flaws but when clear patterns are observed, there is a chance the bullets/cartridges are flawed.