Penetration Question

[Carl N. Brown]

Standard ballistic gel is easy to replicate to a known consistency.

I remember when penetration was measured in 1" thick pine boards in a frame holding boards with 1" airspace between boards. I looked into it. Take a 10 foot by 6" by 1" pine plank, cut it into 6" x 6" x 1" sections, reject sections with knots or cracks, and still there would be variations. No wonder ballistics gel replaced that as bullet test media.

 

[Gridley]

A bunch of people have made a bunch of good points. In particular, that while ballistic gel was designed to be similar to flesh, the overriding concern was to provide a media to allow repeatable testing. The FBI picked a standard penetration through *ballistic gel* that they felt would give sufficient penetration into a wide range of *human bodies* to inflict disabling wounds. To make this explicit: 12" penetration in ballistic gel IS NOT intended to equate to 12" penetration into the human body. If the human body were made of average density human tissue it would... but the human body would then be unable to stand. Or breath. Or...

Also remember, the FBI had to quite reasonably allow for a wide range of body types, and has understood the need to breach light cover at least since the prohibition era.

My only real original contribution here is to note that I've seen three GSWs up close and bloody. Only one penetrated something like 12"... and it was non-fatal. It was also a .22LR, and fired from a pistol to boot. The one fatality was from a .38 special from a short barrel, which penetrated about 8" with.... impressive... fragmentation. I'm sure you can look up the performance of typical .22LR and typical .38 special in ballistic gel.

 

[Don Dayacetah]

Whenever this comes up, I point out that not everyone--me included--sees this as the absolute the FBI does.
1: the FBI needs rounds that will put someone down, immediately. I'm a lot less likely to meet anyone as determined as they are.
2: the FBI has to take into account cover and penetration through vehicles. If that becomes the situation in my case, that means that A) they are leaving or B) I have to be more worried about not being in the way. Expansion after barrier penetration only factors into my decision if the round already functions as well as another otherwise.
3: those numbers are in gelatin. A human body ranges between that consistency, bone, and open space. Any given round is just as likely to expand less as it is to expand as neatly as gelatin will get it to.

That said, i will not fault anyone for carrying something that conforms to FBI standards.
In my case, though, I also won't fault anyone for carrying something that expands well but penetrates slightly less. I consider about 8" or 9" in gelatin to be getting into the 'about right' range, as long as it expands well within that distance and it can be put in the areas it needs to go.
I consider wound volume important. IMO something that expands to .8" in 9" of gelatin is likely to work just as well on your standard street goblin as something that expands to .5" in 14".
If a 9" wound doesn't hit anything vital in the five-to-sixteen rounds I'd end up sending their way, I guarantee I can outrun them. If that big expansion doesn't happen in the inconsistent mass of a human body, the round's likely to penetrate deeper. Win-win.

If someone doesn't subscribe to my same opinion and wants to limit themselves to the standards the FBI set, that's cool. They're FBI standards for a reason.

Folks DO go on about those FBI standards. And IMO, the FBI has concluded that these standards are ANYTHING BUT an "absolute".
If the FBI is SO adamant about penetration, why did they puss out, and drop the 10MM round, altogether?

Another old saw that's dull and rusty, and needs to be put to bed, is that outstretched forearm"blocking penetration" theory. Anybody else see somebody shot through 12" of the bone, nerves, muscle, tendons and cartilage that reside in a hand, wrist, forearm and elbow? Because the folks I've seen shot through the forearm all ended up on the ground, writhing in agony, regardless of where the bullet went next. Anybody here observed anything different?

 

[JeffG]

Because the folks I've seen shot through the forearm all ended up on the ground, writhing in agony, regardless of where the bullet went next. Anybody here observed anything different?

Yup! I've seen a few shot through the outstretched hand, into the face too; not much writhing after that.

 

[RetiredUSNChief]

For years I’ve read everywhere that a minimum of 12” of penetration is generally accepted as necessary for a load to be considered as good to carry. Maybe I’m just not getting it, but it seems to me that most of the bad guys I see getting shot might only be 12” front to back and quite a few others would still only need 6-10” of penetration to get to the good parts. Barriers notwithstanding, just bad guys in regular clothes, it just seems to me that 8-10” of penetration should suffice with not much chance of over penetration in most cases.

Please help me to understand this, as I realize all the time and money spent over the last few decades , testing that was done by many agencies and companies, etc. seems valid, and real world incidents provide valuable info, but I’m just imagining thousands of druggies that are maybe 12” deep couldn’t stop a bullet with 14-18” of penetration. Am I wrong?

It's a reasonable rule of thumb that was established by the FBI a number of years ago.

And, as standards go, it's a pretty good one, in my opinion.

Remember...the human body isn't a uniform thing. We clothe it, we position it in different postures, we grow them all kinds of different sizes, and they're structured around a hard skeleton. There are a variety of things which affect penetration, in other words.

A bullet which will penetrate at least 12 inches will therefore have a good chance of reaching vital organs in the vast number of circumstances.

That's all it means...don't get too hung up on all the details and bruhaha about it.

 

[Shawn Dodson]

Minimum penetration depth of 12" is based on informed medical opinion.

Properly prepared and calibrated ordnance gelatin does indeed accurately replicate soft tissues encountered by a penetrating bullet. Fackler's wound profile illustrations were developed from bullets shot into ordnance gelatin - they accurately depict the wounding mechanisms and wound trauma produced in human soft tissues.

 

[JeffG]

Always good (re) reading...

https://archive.org/stream/Gunshot_...arms_Ballistics__Forensic_Techniques_djvu.txt

 

[Odd Job]

Another old saw that's dull and rusty, and needs to be put to bed, is that outstretched forearm"blocking penetration" theory. Anybody else see somebody shot through 12" of the bone, nerves, muscle, tendons and cartilage that reside in a hand, wrist, forearm and elbow?

I have seen a lot of gunshot wounds in the ER setting. More than 3000, in Johannesburg.
I can tell you that shots through the hands and forearms are quite common because it is a natural reaction to raise your arms up in defense. How much the bullet will penetrate depends on many factors. Some of these factors are:

1) The velocity of the projectile on impact (assuming the mass of the projectile when coupled with that velocity is conducive to penetration).
2) The construction of the projectile. You'll do better with ball than a Glaser or other frangible for example. The more it holds together, the less likely it will shed mass in the terminal trajectory.
3) The nature of intervening clothing, if any. It could be a heavy coat sleeve for example.
4) The presentation of tissues in the terminal trajectory. That's not only the question of bone vs muscle and fat, but also the alignment of these tissues. If a bullet gets into a tissue plane it can travel quite far with much less resistance than if it has to cross a muscle. Also, a bullet will get through a flat bone a lot easier than the cortical bone of long bone.

I've seen a .380 enter at the base of a woman's little finger whilst her arm was outstretched in a defensive posture. It was an FMJ fired not more than a few feet away and it broke a lot of bones in the hand, chipped a piece of radius near the elbow, and ended up behind the humerus at the back of the elbow. That's quite a long trajectory for a humble .380 and it may well be that the bullet found a tissue plane in the forearm and therefore was subject to far less resistance in that part of the trajectory.
Nonetheless a lot of bones were broken in the hand and wrist.

Bullets do strange things...

 

[jmr40]

I still maintain that outside of actual living humans, live animals are the most objective test medium.

I disagree. It MIGHT be reliable if you were to shoot hundreds of animals and get an average of the results. I'm primarily a hunter and have seen too many animals shot. I've seen 150 lb deer drop in their tracks from a 223 and seen others run over 100 yards after being hit in the same location with a 30-06. For a variety of reasons living creatures react differently when shot and it is too easy to reach false conclusions.

Ballistic gel is the same all the time. A bullet that penetrates 12" in gel may not always penetrate 12" inches when shot into living flesh. Depending on the resistance it meets it could penetrate 20" or 6" in flesh. But a bullet that penetrates 12" in gel will on average penetrate deeper than a bullet that only penetrated 8" in gel. I think 12" is a good minimum, and I'd like more. Depending on the shot angle 10" of penetration still may not reach vital organs.

 

[Odd Job]

I can tell you that shots through the hands and forearms are quite common because it is a natural reaction to raise your arms up in defense.

The other obvious scenario, aside from defensive posture is the outstretched hand holding a gun or knife in offensive posture. I forgot to add that earlier.

 

[Sarge7402]

What makes you think you're most likely going to have a full frontal target?

If it's not a full frontal you will need to be able to explain to the police and maybe even a grand jury how some one not facing you posed a threat to you. Perhaps a loved one is in danger. But if you are not in immediate danger your right to self defense starts to get tricky

 

[Zaydok Allen]

Ballistic gel is the same all the time.

Exactly. Law enforcement, ballisticians, the FBI and all the rest of us need a consistent test media.

If we don't have a standard, then testing will be all over the place, and demonstrates nothing.

Can you imagine if the FBI or law enforcement tested ammo on living animals? Dear god, PETA would riot.

As long as people understand that a living body has too much variance in density to expect 100% gel test like results, then we are good. I think gel tests are most applicable to non-expanding, hard cast or monolithic bullets designed to track on a straight path. But even then, bone and density variation can impact the wound track.

 

[Sarge7402]

This is it. The standard is totally semi-arbitrary and based almost exclusively on that one event. Of all the possible conclusions from analysis of the event, the FBI's conclusion was that there was an ammunition failure. They created an arbitrary standard by crafting calibrated ballistic gel and setting a specification for penetration they believed would prevent insufficient penetration. The gel standard specifications are based on Michael Platt's body, but they are convenient, repeatable, and offer consistency in media as a fair basis of comparison in expansion and penetration.

Importantly, ammunition makers followed it. Gunzine writers, blog writers, and reviewers doing their own testing and evaluation (most notably in the last couple years the frequently cited Luckygunner tests) follow it. It has been widely followed since 1989.

The FBI dismissed concerns about overpenetration, publishing that since the overwhelming majority of shots fired by law enforcement do not hit the target, it was unreasonable to be more concerned with overpenetration of the ones that do hit the target. For reference, in the '86 Miami shootout, over 145 rounds were fired in less than 5 minutes. But we should be worried about overpenetration?

You are correct in your assumption that the FBI fixated on bullet failure in their initial evaluation of the event. However others including Mas Ayobb have done a much better job of analyzing the event and drawing other conclusions. Such as bad tactics etc.

Also since most gunwriters only deal with firearms and ammo - not like LE magazines that try to address the entire event in any given shooting - there are very few ways to evaluate ammo. You Have Eva Marshall's one stop data http://www.familyfriendsfirearms.com/Stopping Power Statistics.htm , and the stasborg goat tests http://guninstructor.net/Strasborg_Tests.pdf and the penetration in balistic gel to give a average street guy (or small town pd) any idea of how a particular ammo will perform

 

[Blue Feather]

Use a proven caliber in a proven load verified by multiple LEO incidents and be happy.

 

[Deus Machina]

Use a proven caliber in a proven load verified by multiple LEO incidents and be happy.

This is about what it comes down to.
Use a 'premium' round from a large manufacturer that you can research.
Not the new whiz-bang wonderbullet (it seems they often expand or, more often, fragment without much penetration) and rarely the 'budget' JHP, which may penetrate but may or may not expand.
My rule of thumb: HST or Gold Dot of any flavor. These expand and function well under 90% of circumstances. They don't function? Pow'r Ball. Have a revolver and don't want the hotter stuff for whatever reason or you're traditional? Lead semi-wadcutter HP.
99.9% of the time, there's no reason to look outside of these 4 selections until another big advancement in design comes through.

 

[RPZ]

I disagree. It MIGHT be reliable if you were to shoot hundreds of animals and get an average of the results. I'm primarily a hunter and have seen too many animals shot. I've seen 150 lb deer drop in their tracks from a 223 and seen others run over 100 yards after being hit in the same location with a 30-06. For a variety of reasons living creatures react differently when shot and it is too easy to reach false conclusions.

Ballistic gel is the same all the time. A bullet that penetrates 12" in gel may not always penetrate 12" inches when shot into living flesh. Depending on the resistance it meets it could penetrate 20" or 6" in flesh. But a bullet that penetrates 12" in gel will on average penetrate deeper than a bullet that only penetrated 8" in gel. I think 12" is a good minimum, and I'd like more. Depending on the shot angle 10" of penetration still may not reach vital organs.

Animals react differently to humans when shot because of their instinctive reactions to injury and pain versus humans who are influenced by other things.

However, I was not referring to reactions, rather bullet performance - like penetration and tissue damage.

As far as sampling goes, many, many thousands of deer, pigs etc have been shot - and continue to be - with service caliber handguns.

 

[RPZ]

Exactly. Law enforcement, ballisticians, the FBI and all the rest of us need a consistent test media.

If we don't have a standard, then testing will be all over the place, and demonstrates nothing.

Can you imagine if the FBI or law enforcement tested ammo on living animals? Dear god, PETA would riot.

As long as people understand that a living body has too much variance in density to expect 100% gel test like results, then we are good. I think gel tests are most applicable to non-expanding, hard cast or monolithic bullets designed to track on a straight path. But even then, bone and density variation can impact the wound track.

I'm not suggesting the FBI might shoot a few thousand goats. Rather, as individuals, we can glean plenty of useful info in the subject from hunters who have shot light to medium size game animals using specific loads.

 

[RecoilRob]

The conundrum is that a particular bullet design that works the best in one scenario will fail miserably in another. Take the Glaser Safety Slug for example......in a frontal chest shot on an unarmored human it's going to work most excellently....but if the shot includes needing to penetrate through much muscle or bone...forget anything but a gory surface wound that won't incapacitate a determined foe.

So for best coverage of ANY scenario that you might encounter means a compromise must be met which balances penetration against possible expansion or fragmentation....with penetration being the most important criteria. Any round that will penetrate deep enough in a 'worst case' situation is going to thru-n-thru when it only encounters flesh or less resistance even in a solid hit. Sorry...that's just the way it is. Carry what will penetrate deep enough in the worst case and be careful with your placement and things should work out just fine.

 

[BSA1]

If it's not a full frontal you will need to be able to explain to the police and maybe even a grand jury how some one not facing you posed a threat to you.

Baloney!

I strongly recommend you learn the elements required to use deadly force for self-defense. Your attacker standing straight at you is not one of them.

 

[GRIZ22]

If it's not a full frontal you will need to be able to explain to the police and maybe even a grand jury how some one not facing you posed a threat to you. Perhaps a loved one is in danger. But if you are not in immediate danger your right to self defense starts to get tricky

If your assailant is using cover/concealment, standing at an oblique, someone trying to smash an innocent's head in with a crowbar, or you're being carjacking are some of the many situations you may not have a full frontal shot.

Baloney!

I strongly recommend you learn the elements required to use deadly force for self-defense. Your attacker standing straight at you is not one of them.

Take BSA1's advice.

 

[Odd Job]

It is entirely possible to shoot somebody in the back in a case of self defence, if the shot is fired as the assailant is turning.
It is a subject that was covered by Vincent Di Maio in his book "Gunshot Wounds - Practical Aspects of Firearms, Ballistics, and Forensic Techniques" (second edition). See Chapter 9, page 273 which deals with "Reaction-Response times in handgun shootings"
That section references a study by Tobin and Fackler to do with mean firing times vs mean turning times (both for a 90 degree turn and a 180 degree turn). The citation for that article is:

Tobin, E. J., & Fackler, M. L. (1997). Officer reaction-response times in firing a hand gun. Wound Ballistics Review: Journal of the International Wound Ballistics Association, 3(1), 6-9.

Having said that, much will depend on whether the circumstances of the shooting as described in court are compatible with that kind of legal defense. It's not a sure-thing!

 

[Blue Feather]

You can’t overthink this. For starters, as a legal concealed carrier, all you are doing is trying to stop the threat nothing more; nothing less.

Look at the rounds with proven success stories as I stated earlier. .357, .45, .40 and now some 9mm rounds. Note: Look at LEO statistics not veiled advertising posing as information coming from ammo manufacturers or firearms producers in the form of a gun magazine article or TV show content.

IMHO, home defense is a “ whole nuther story “ and one I feel is best handled with a shotgun.

 

[Wichaka]

Years ago I was able to do some ballistic research and came up with a short non-definitive study.

I was fortunate in my LE career to be forensic trained. In that time I attended many autopsies, and was able to assist with many.

What started my ballistic research...One time I was waiting for a victim of case I was working to be done, but there was a gunshot victim from another agency before me. I was allowed to watch, photograph and have them slow down to examine the entrance, bullet path etc. Once that was over I asked if at any time they had a gunshot victim to please call me any time day or night, as I wanted to do my own research on the subject.
I was also fortunate to be able to do the same in a neighboring state at their lab, both were extremely helpful and knowledgeable and provided me with a lot of valuable information about what I was doing, and went out of his way to make this research possible.

Overall I was able to attend and document 42 shooting victims in a span of almost 5 years, from 2003 to 2008. Examine bullet entrance and exit, if there was one. Bullet path, damage, and projectile diameter, weight and make, model ID.

I also gathered data from LE shootings from NW agencies and added what I could into the research, because I was able to positively ID the bullet make and model and some information as to the victim size, weight, distance of the shot and angle etc.

Some of what I learned, I never found in any book on the subject. I have read most every book out there about ballistics, even the famed Stopping Power book by Marshall & Sanow, which I thought was lacking.

What I learned;

Pistols don't produce enough power to effectively have consistent bullet performance. aka pistol bullet performance sucks.

In talking with a friend of mine who's an engineer for ATK, but overall works for Federal - Speer - CCI, creating a HP round is a delicate matter. If the velocity is too great, the HP opens up too fast creating a parachute affect, thus not getting penetration. If it goes too slow, the HP won't open up and will act like a FMJ.

Folks don't realize the differences in each human that can affect bullet performance. Things such as age, medications, drug use, smoker, weight, muscle density etc., all have affect on skin, organ and bone density...which affects bullet performance. Even race, culture and place of residence around the world have some bearing. This information came from one of the Dr's which spent many hours with me going thru this part of the study, showing me the differences...fascinating...to me anyway.

One can shoot 6 different people in the same place, with the same caliber and bullet and get 6 slightly different results. Why 6?, because I witnessed it myself through the autopsies.

Some bullets were hard to identify as to make and model, but others were readily identifiable. After a few victims where I was able to identify the bullet, I would receive a call now and then from a med examiner asking if I could make an ID for them.

A person can be shot through the heart, and sometimes totally destroy the heart and still live over 2 minutes. A lot of damage can be done in that amount of time.

9mm is what I found to be the absolute smallest pistol caliber to use/carry. And #4 or #6 shot is way more effective than 00 Buck. Yes, I know .22 rimfire and other small calibers have killed many a person, but the smaller calibers needs even more emphasis on shot placement.

9mm = .355"; 40 = .400"; 44 = .429" 45acp = .452"

Stay away from the gimmick bullets, and go with a solid constructed HP. What works in ballistic gelatin, wet newspapers, even live or dead animals is not the same performance you'll see in human media.

Bonded bullets work well when going through media such as glass, boards etc., but lack consistent performance when entering a human without going through the above first, won't get consistent reliable expansion.

Finally, shot placement is paramount...Period! If a bullet doesn't go in the snot-locker, you'll be waiting for the person to faint. Yes, that is the medical term for someone who loses enough blood pressure...they will faint. More bullet holes, equal faster blood loss, which in turn lowers the blood pressure until the person faints. So the ultimate goal of such a confrontation is to have the threat faint really really fast...unless there's the snot-locker shot.

Another person I relied on was Dr. Gary K Roberts. He came to our state LE firearms instructor conference some years ago and made a ballistic presentation, and I was able to compare some things with him, and confirm some of what I was seeing. What I liked about his presentation is that it dispelled some of the myths in the firearm ammo community. Attending his presentation were some ammo manufacturer reps we had there, they were not happy to hear that some of their product was junk.

My study is in no way definitive, but each autopsy and other shooting info kept proving the above...and gave me information that I felt was not available to the public.

 

[Sarge7402]

Baloney!

I strongly recommend you learn the elements required to use deadly force for self-defense. Your attacker standing straight at you is not one of them.

First I do know full well the requirements for being able to use deadly force. All I said was you'd better be able to articulate your circumstances to either the police or to a grand jury.

 

[Zaydok Allen]

Years ago I was able to do some ballistic research and came up with a short non-definitive study.

I was fortunate in my LE career to be forensic trained. In that time I attended many autopsies, and was able to assist with many.

What started my ballistic research...One time I was waiting for a victim of case I was working to be done, but there was a gunshot victim from another agency before me. I was allowed to watch, photograph and have them slow down to examine the entrance, bullet path etc. Once that was over I asked if at any time they had a gunshot victim to please call me any time day or night, as I wanted to do my own research on the subject.
I was also fortunate to be able to do the same in a neighboring state at their lab, both were extremely helpful and knowledgeable and provided me with a lot of valuable information about what I was doing, and went out of his way to make this research possible.

Overall I was able to attend and document 42 shooting victims in a span of almost 5 years, from 2003 to 2008. Examine bullet entrance and exit, if there was one. Bullet path, damage, and projectile diameter, weight and make, model ID.

I also gathered data from LE shootings from NW agencies and added what I could into the research, because I was able to positively ID the bullet make and model and some information as to the victim size, weight, distance of the shot and angle etc.

Some of what I learned, I never found in any book on the subject. I have read most every book out there about ballistics, even the famed Stopping Power book by Marshall & Sanow, which I thought was lacking.

What I learned;

Pistols don't produce enough power to effectively have consistent bullet performance. aka pistol bullet performance sucks.

In talking with a friend of mine who's an engineer for ATK, but overall works for Federal - Speer - CCI, creating a HP round is a delicate matter. If the velocity is too great, the HP opens up too fast creating a parachute affect, thus not getting penetration. If it goes too slow, the HP won't open up and will act like a FMJ.

Folks don't realize the differences in each human that can affect bullet performance. Things such as age, medications, drug use, smoker, weight, muscle density etc., all have affect on skin, organ and bone density...which affects bullet performance. Even race, culture and place of residence around the world have some bearing. This information came from one of the Dr's which spent many hours with me going thru this part of the study, showing me the differences...fascinating...to me anyway.

One can shoot 6 different people in the same place, with the same caliber and bullet and get 6 slightly different results. Why 6?, because I witnessed it myself through the autopsies.

Some bullets were hard to identify as to make and model, but others were readily identifiable. After a few victims where I was able to identify the bullet, I would receive a call now and then from a med examiner asking if I could make an ID for them.

A person can be shot through the heart, and sometimes totally destroy the heart and still live over 2 minutes. A lot of damage can be done in that amount of time.

9mm is what I found to be the absolute smallest pistol caliber to use/carry. And #4 or #6 shot is way more effective than 00 Buck. Yes, I know .22 rimfire and other small calibers have killed many a person, but the smaller calibers needs even more emphasis on shot placement.

9mm = .355"; 40 = .400"; 44 = .429" 45acp = .452"

Stay away from the gimmick bullets, and go with a solid constructed HP. What works in ballistic gelatin, wet newspapers, even live or dead animals is not the same performance you'll see in human media.

Bonded bullets work well when going through media such as glass, boards etc., but lack consistent performance when entering a human without going through the above first, won't get consistent reliable expansion.

Finally, shot placement is paramount...Period! If a bullet doesn't go in the snot-locker, you'll be waiting for the person to faint. Yes, that is the medical term for someone who loses enough blood pressure...they will faint. More bullet holes, equal faster blood loss, which in turn lowers the blood pressure until the person faints. So the ultimate goal of such a confrontation is to have the threat faint really really fast...unless there's the snot-locker shot.

Another person I relied on was Dr. Gary K Roberts. He came to our state LE firearms instructor conference some years ago and made a ballistic presentation, and I was able to compare some things with him, and confirm some of what I was seeing. What I liked about his presentation is that it dispelled some of the myths in the firearm ammo community. Attending his presentation were some ammo manufacturer reps we had there, they were not happy to hear that some of their product was junk.

My study is in no way definitive, but each autopsy and other shooting info kept proving the above...and gave me information that I felt was not available to the public.

Is your study published? I'd like to read it.