My question may provoke more outrage than information, but I'm concerned enough to ask.  As I recall from my repeated research, the FBI/DOJ standards for ammunition performance were developed in response to the Miami shootout and aftermath. Most modern anallysts seem to think the reason the gunfight was so disastrous was because of bad tactical decisions, and yet the Bureau, in normal fashion, went looking for a hardware solution.  They chose (at least in part) to blame "underpenetrating ammunition" for failing to stop the shootout.    My memory tells me one of the perpetrators was hit with a slug that followed a rather indirect path bouncing off bones and lodging near his heart, but the resulting "standard" set the penetration guidance shorter than the round that was said to underpenetrate. In other words, "penetration is key, and we want to make sure we use stuff that doesnt do as well as what failed here".  Obviously this would not be an intentional choice, but it looks to me like this is what happened. Today I'm unable to find the articles I read in the past regarding the details and the autopsy reports.  Can anyone post a link to an article, perhaps Ayoob's reconstruction, with that information?  Or maybe something that shows me I'm just wrong on the facts of "failed bullet penetration exceeds FBI guidance".    If I'm right I want to know why everyone evaluates their ammunition choices on conformance to a bad bureacrat's political decision.   I'm also weary of ammo makers boasting "we exceed the FBI standards"  and i just need to get over it.

We just did this a few days ago.

There were several links posted; haven't had a chance to follow them all yet.

Thread is open on my laptop; I'm on my iPad.

Whether the FBI chose an arbitrary performance standard or not, I think the point is that the testing is standardized so the relative performance of different ammo can be compared.

It's like TNOutdoors9 and his ammo testing:  he's consistent so one can objectively compare the performance of one round to another.

There were many failures that day. Some hardware related, others not so much.

As far as "why" the FBI picked the numbers they did... the had a lot of data from a lot of places to sort through. I think there was more than just the single bullet the under penetrated that day. IIRC they originally suggested deeper penetration than is the current standard (12-18" being "ideal"), and later revised the numbers as bullets improved in response to FBI tests. I think the original numbers were closer to 14-20" of penetration as ideal. I personally like a bit deeper penetration out of a defense load. But I also come from a school of thought that a big game animal can't walk very far if it's got broken shoulders, so I may be biased.

There was a study about what the old OSM 147gr JHP (same as the current WW "white box 147 JHP) did in a large number of shootings in a California LE agency, that data was correlated to what that load did in 10% gel with various barriers (going by memory here). I think there have been further studies along the same lines, that have added to this one.

The various tests are not really supposed to simulate a body, with bones, organs and clothing outside, so much as to test the bullets resistance to plugging of the cavity and give some idea of expansion characteristics, along with penetration info. I've seen it said in more than one place, by people examining LE shootings, that the bullets "good" loads pulled out of dead criminals are often almost identical to 4-layer denim gel tests, unless they hit a major bone or some other hard barrier before or after. They are often found in the far side clothing, or just a short distance behind.

This is a good start: https://www.ar15.com/ammo/project/Self_Defense_Ammo_FAQ/

Personally, I want a bullet that does its job if I do mine. I want a bullet that willl pass through the spine of a muscular 20lb man from any angle. Gel is helpful to test how well a hollowpoint opens up and to compare its oenetration to other bullets in a co trilled environment.


There are some fliers that underpenetrate some in gel but do well on the street (federal 9PBLE, 125gr .357 mag, Corbon 115gr +P)

Where did you get that 9bple under penetrates??

Both the Fed 9BPLE and the venerable 357Mag 125JHP's average around 9-10" in bare gel. The FBI totally disregarded these two loads as being acceptable, and yet these loads have a proven tract record with LE use (especially the 9mm +P+ loads by both Fed and Win as used by the Illinois State Police).

Im at work but just search "9PBLE gel" on youtube. Whether it underpenetrates for YOU depends on what you want.

Its an interesting option and I wouldnt tell you to not carry it. The new DPX expands to .86 and does 12-14in (meets minimum) as well as does better on barriers, so Id rather carry that if I wanted less penetration.

I understand gel does not exactly replicate human tissue. That was really not the source of my questions the question was the self cancellation of the FBI's position which I elaborated on in my original post.   I also don't want to create a fackler vs Marshall and Sanow debate

I guess I am confused, the Silvertip seems to not meet the FBI minimum penetration consistently:

https://m.youtube.com/watch?v=HztD9GKtLUw

Gold dots and HST exceed the minimum and the bullets often dont pass through the bad guy, or are found inside clothing.

On the topic, from what ive read i done onow why 15in isnt the minimum, as the Silvertip that failed seems to do about 11in.

Where are you guys getting this?    Before I posted, I DID in fact recheck my thinking.  9-10"......not what I saw.  I saw from 12-18".   Tnoutdoors who's been very consistent and reliable measured it at 13.25".   Bare gel????   Um no.   4 layers of denim, per the spec.  Sorry, but I think this is being misquoted.

It will also depend on the bullet used, as well as what happened in different tests done by different people. Sometimes 9PBLE will penetrate past 12in, sometimes not. If you prefer deep penetration over speed, 147gr Gold Dot is better. But what you prefer is your own choice.

Honestly both loads are good. 125gr .357 mag is good, if you want more penetration then go with 158gr Gold Dot.

124gr +P+ gold dots from Underwood look pretty mean.  

At best, pistols are crappy fight stoppers.  Your best choice is to shoot fast, accurate, and a lot, best I can figure, should you have to.

To return to OP's original question: he is exactly correct that the immediate reaction of FBI was to blame the hardware. In fact, there was not a "depth of penetration" measurement in the original autopsy. I have a copy of the autopsy report, and it is to be found in W.F. Anderson's analysis (avail on Amazon). That apparent omission is not surprising, since forensic pathologists only rarely do so now, and we pretty much never made that measurement way back then. The depth estimation was later made from X-rays. Like almost all pistol bullets, that particular bullet traveled in a fairly straight line, but it did hit the arm first, resulting in an "entrance-exit-reentrance" pathway. Whatever the exact depth was is immaterial; the rush to blame the hardware had the unintended consequence of establishing standards, something that simply did not exist at that time.
Remember that this was the "temporary cavity/RII" era of fast, light projectiles, where violent expansion (even fragmentation) was deemed desirable. Most formal research was being done on rifle bullets using soft soap as the test medium, and the few people using ballistic gelatin couldn't even agree on whether 10% or 20% was more accurate. Nobody had any standards - or even guidelines - for testing pistol bullets in anything like a realistic fashion.
It is no secret that the Handgun Wounding Factors and Effectiveness Group had a few outspoken members with a "big bore" slant, but that, too is very understandable given the times. Ammo companies had not put any significant effort into wound ballistics, because there were no standards to design around. With the simple "cup-and-core" hollowpoints of the day, you had to drive them at supersonic velocities to have any confidence in them opening. When they worked, they worked well, but they failed a large proportion of the time. The big bores were not as spectacular, but they were far more reliable, especially if intermediate targets were encountered.

The beautiful result of this less-than-ideal, confused, politicized background is that there was sufficient input from outside the insular FBI world to lead to establishment of a fairly realistic set of standards. For the first time, ammo companies had something concrete to use as a design goal. That these standards have turned out to be pretty robust speaks well to the intellectual honesty of the group.

Thank you for the background info.

It is still my understanding that the 115gr Silvertip would underpenetrate in ballistics gel and would not pass the FBI test if tested today.

Also I didnt comment on this but just to be clear, yes the main mistakes were poor preparation and training, etc, missing from 6 feet, etc.

there may not have been a "depth of penetration" measurement, but there was a "the 115gr Silvertip stopped 1/2" short of the guys heart" measurement

Ignoring the fact that he should have been riddled with bullets anyhow, I would venture a guess that 124gr XTP or Gold Dot would have penetrated the heart.

I'm no expert but my understanding from online tests I've seen is the 115gr silvertip of the time is okay but it WOULD not pass the FBI test today. I'm open to being wrong....

Why FBI testing? Short answer is they have the money, man power, labs and resources to do this kind of thing.
The shoot out in question was a train wreck in a bag.
FBI testing is done at a measured distance and a secondary distance. The gel has to be of a certain temperature, calibrated with a BB shot at 350 FPS, I think, others can confirm or correct this, and has to be of a certain composition.
The idea is a measurable, repeatable, and consistent test. They did that very well. Even at that some argue the distances and such are unrealistic. Oh and they studied the distance averages in shootings as well, so,,,,,,,,,,,,,
The gel mimics muscle tissue. It gives a good indicator of what the bullets are doing inside a target, that is, measurable.
Lots of folks harp on gel this or that, and it is a good window into the terminal performance of a round, but there is another factor. When they get X results in gel, they should expect Y results in a living target. Not may people fit the dimensions they propose for performance in gel. Not many people are muscle tissue though their thorax area either.
Happy Obsessing

The fbi lowered their standards for the female and weak statured shooters.  That said I believe there's some merit to having more rounds at hand.

American Rifleman, June, 1990

The FBI Ammo Tests

Really nice article. Thanks!

8 to 10" is plenty of penetration in a direct torso shot.  And the record with these rounds is, as you say, quite proven in those circumstances.

The FBI wanted a minimum 14" (later changed to 12") because they wanted penetration through a shoulder or arm in addition to the torso.  That's the justification.

A perfect, static shot through the torso, head on isn't always possible.

8 to 10 inches in gel is not 8 to 10 inches in a body. Gel is just a medium that simulates muscle for expansion and if calibrated correctly, it'll produce repeatable results. Because it produces repeatable results, different bullets can be tested and compared.

So why is 8 to 10 inches in gel not the same as a body? To calibrate gel, a BB going at 590 fps must penetrate 3 to 4 inches in the gel. That same BB will not penetrate your skin, go through bone, and reach your heart 4 inches deep. It'll barely break your skin.

So you want a round that penetrates more than 12 inches in gel. 12 inches is the absolute minimum.

Pray tell, gentlemen, where this "street and proven tract record" information might come from?

Velocity is a very important factor in bullet behavior.  For example a standard velocity 115 grain Silvertip out of a 4” model 59 usually chronographs at 1150 FPS.  The WW 115 grain +P+ will usually chronograph at 1300 FPS out of the same 4” barrel.  The 115 grain bullets at higher velocity will shed more mass as they go through the target.  Many times the petals will be torn away from the body of the bullet leaving a diameter size lead in copper cup when recovered.  The 125 grain 357 magnum bullets behave the same way.  With the petals sheared away the bullet actually penetrates deeper with the higher velocity.  The slower velocities tend to leave the bullet with a full mushroom with bigger diameter which reduces penetration.  As a LE Officer I dispatched many deer with handguns.  The deer were given to people to try and use the animal.  I had people I knew who came to get the deer and they recovered several projectiles for me over the years.   I used several different handguns over the years to dispatch deer and the results were interesting.   I have also tested many bullets in water filled gallon jugs to gauge performance.  

In the real world cup and core bullets don’t behave the same in every shooting.  In one shooting a subject was shot in the torso with a 9 MM at close range and the bullet showed no expansion but stopped the adversary quickly.    I spoke to the Crime Scene tech who was at the autopsy of many shooting victims.   I think the newer designed bullets like HST have greater likelyhood of performing consistently in respect to expansion and penetration.

In the past it was not always known for sure who manufactured the JHP bullet used in a shooting which can skew the results.  Add in the different velocities due to different barrel lengths and distance to target further complicate things let alone the different human size structure of the target.   The ISP was satisfied with the street performance of the 115 grain JHP +P+ ammo.   The ISP reviewed the FBI recommendation on the low velocity 147 grain JHP and decided to stay with a cartridge which had previously performed satisfactorily on the street.

It is a valid concern that a bullet may well need to penetrate through arms or other objects before entering into the torso of an aggressor.  It is also a concern if a bullect perforates a torso with enough kinetic energy to give a lethal wound to an innocent bystander.   My Agency was very concerned with fraticide and had good training.   We trained more than many agencies and were taught to shoot till the aggressor was stopped.   Fortunately my agency didn’t have any fratricide which was attributed to bullet/ammo perforation while I was employed and with the issued 9 MM or 40 caliber handguns.

For police departments this might be a valid concern.  For civilian defensive shooters, it is more likely that an innocent bystander will be struck by lightning than by a bullet emerging from a miscreant.

It cannot come from Marshall, who used the "street proven track record" and tried to apply a little rigor to it.

So instead, we just use confirmation bias(although, since we are so very scientific we don't call it that).

Clear it up for you?

My friend and I were talking about this the other day and he sent me this link to an FBI article.
Maybe this is already well known but I did not see it linked in this thread:

FBI Justification

Camel = horse designed by committee.

Just to be  clear, are you disagreeing with the statement that 125 .357 mag and 9PBLE have good street records? Do you think the data is skewed?

I'm asking where the data comes from.