Are Penetration and Expansion minimums enough?

[WrongHanded]

Recent threads on handgun cartridge efficacy and wounding mechanisms, and cartridge comparisons, have had me doing more research and general looking around. I can always trust such threads on THR to get me thinking about what really matters or doesn't, and why.

We all know (or should), that the basic part of the FBI cartridge qualification tests are that a bullet penetrate between 12" to 18" into ballistic gel through 4 layers of denim, and expand to at least 150% of the bullet's unexpanded diameter. The FBI has additional testing of course, and they use a particular kind of gel that is "calibrated" prior to testing. They also have some other specifics to the testing protocols not commonly spoken of. But let's not get bogged down in the minutiae.

Instead let's for a moment consider that it is widely believed the only way a handgun bullet can created wounding with any reliability, is from crushing the tissue directly in its path. That would mean a tubular wound approximately the diameter of the expanded bullet. Whether or not this is accurate has no bearing on the fact that this is what is commonly considered the truth. So let's for a moment consider it is.

Here we have a .22 Magnum load from Hornady, that from a 4.3" KelTec does meet the penetration and expansion requirements (you may have to select the 4.3" barrel in the small drop down menu):

https://www.luckygunner.com/22-wmr-45-gr-ftx-critical-defense-hornady-50-rounds#geltest

Based on the commonly accepted "truths" about what a handgun bullet can do and what the FBI says is important, is this cartridge not all a person would need?

Yes, I know it's a rimfire. But if it goes bang reliably, that's all that matters. To be determined in each individual carry pistol.

 

[Risky buisness]

Odd thing about testing are the variables that may not be included in the parameters.
Deflection from an object, bone, cigarette lighter, metal button. Angles figure into the equation as well.
Will a particular projectile that preforms to a specfied arbitrary net result set as a minimum standard be sufficient to end an event?
Arguable and subjective. One has to have a baseline for a measurable result to start with.
On paper, or a test medium, it appears the .22 mag is sufficient. That isn't arguable, for the test purposes at least, provide the answer.
The subjective portion then becomes the arguable.
My bottom line is to accept that a certain caliber has an extra amount from the minimum specification considering velocities, frontal area, weight and construction on the mechanical side, and on the functional side, include recoil managment, functional accuracy, capacity and ease of use.
Add perhaps, availability of that ammunition, cost of practice ammunition that may duplicate some of the characteristics of your chosen round.
By now, when you add personal choice, and biases, cost of the hangun and their you have it. It's all your choice.

 

[Skribs]

Instead let's for a moment consider that it is widely believed the only way a handgun bullet can created wounding with any reliability, is from crushing the tissue directly in its path. That would mean a tubular wound approximately the diameter of the expanded bullet.

I used to believe this, but to be honest, I don't even think this is widely believed anymore. For example, my understanding now is that between a pointed FMJ, a flat-nose FMJ, and a wadcutter, you're going to crush more the less "rounded" or "pointed" the bullet is. Flat-faced bullets crush. Pointed bullets can instead push stuff out of the way, and if it is not broken in the process, the tissue will snap back into place. Look at almost every ballistic gel test (including the one you linked) and you'll notice the "neck" of the wound channel is thinner than the bullet.

To answer the question posed in the title, I think minimums are just that. The minimum. At least by this testing standard. Personally, I prefer to go a bit deeper. I'd rather make sure that energy is carrying through into where I need it the most. That's why I carry FMJ in my LCP.

 

[JTHunter]

Something that I do to the hollow-point bullets I use is to take a razorknife (box cutter) and gently put 4 to 6 notches around the rim of the HP. This works best on SJHPs as the ones that are "guilded" all the way up are harder. Those I usually just score the grooves on the sides of the bullets. This will let the bullets expand more easily than they might otherwise.
At least they do when shot into a water trough.

 

[CDW4ME]

I submit manufacturer testing versus Lucky Gunner to this discussion.
http://www.le.vistaoutdoor.com/wound_ballistics/load_comparison/load_comparison.aspx
Heavy clothed gel as tested by the maker:
9mm 124 HST - 12'' / .59
9mm 124 HST +P - 13'' / .61
9mm 147 HST - 12.5'' / .69
40 S&W 180 HST - 12.5'' / .80

Look at how the same bullets performed in Lucky Gunners clear gel tests:
9mm 124 HST - 18.3'' / .61
9mm 124 HST +P - 18.3'' / .66
9mm 147 HST - 15.2'' .61
40 S&W 180 HST - 18.5'' / .72

A clear (pun intended) difference is that clear gel is showing about 50% more penetration (about 6'') than manufacturer data.

Two hypothesis:
The 22 mag in the OP probably fails to meet 12'' penetration in not clear gel and doesn't really meet 12'' minimum.
The 380 loads tested in those same clear gel tests show inflated penetration too.

 

[mavracer]

IMHO way to much emphasis is put on just meeting the minimum, to the point that you are asking if 12" is enough. Ultimately it might be or it might not. The 9mm Silvertip round that started the shift to the 40 in the 1986 Miami shootout would actually meet the 12" minimum in the FBI heavy clothing test.

 

[WrongHanded]

I submit manufacturer testing versus Lucky Gunner to this discussion.
http://www.le.vistaoutdoor.com/wound_ballistics/load_comparison/load_comparison.aspx
Heavy clothed gel as tested by the maker:
9mm 124 HST - 12'' / .59
9mm 124 HST +P - 13'' / .61
9mm 147 HST - 12.5'' / .69
40 S&W 180 HST - 12.5'' / .80

Look at how the same bullets performed in Lucky Gunners clear gel tests:
9mm 124 HST - 18.3'' / .61
9mm 124 HST +P - 18.3'' / .66
9mm 147 HST - 15.2'' .61
40 S&W 180 HST - 18.5'' / .72

A clear (pun intended) difference is that clear gel is showing about 50% more penetration (about 6'') than manufacturer data.

Two hypothesis:
The 22 mag in the OP probably fails to meet 12'' penetration in not clear gel and doesn't really meet 12'' minimum.
The 380 loads tested in those same clear gel tests show inflated penetration too.

You bring up a good point. Here's another one:

A longer barrel increases velocity. No doubt the vista outdoors testing was done with a 4-4.5" barrel. The Lucky Gunner test was done with (I believe) a 3.5" barrel. If a bullet is pushed faster into gel it can expand more, which can sometime reduce the penetration depth. It can also expand more but then fold back at the edges of the petals due to the extra force applied to it, and still come out with a smaller diameter in some cases.

But your point on gel type is well taken. Though there is one obvious outlier to your conclusion regarding the 50% additional penetration in clear gel. That 147gr 9mm isn't doing that. I also have see a 10mm 200 HST get only 2" difference between gel types. So there's clearly more going on.

However: If the load in the OP, or a similar load, did make the minimum in 10% ballistic gel, the question remains; is it good enough? My guess is that very few people would feel it is.

 

[Atavar]

Something that I do to the hollow-point bullets I use is to take a razorknife (box cutter) and gently put 4 to 6 notches around the rim of the HP. This works best on SJHPs as the ones that are "guilded" all the way up are harder. Those I usually just score the grooves on the sides of the bullets. This will let the bullets expand more easily than they might otherwise.
At least they do when shot into a water trough.

Be careful, you may be creating dumdum bullets which are regulated and illegal in many areas.

 

[trackskippy]

Im beginning to think that people are so hung up on the paper/gel numbers thing, that they have completely missed the reasons why you want power and penetration, and why you want to hit certain things and do so quickly and repetitively so you increase your chances of a good hit in there somewhere amongst all the chaos, and try and bring about a quick resolution to things.

Will that 22mag work? Yes, no, maybe. Where are you shooting them to make it work? Are we saying that a hit "anywhere" is all that's needed to incapacitate? Or are we saying it might, or might not reach a vital organ and do enough damage, to start the process of stopping things? And of course, that assumes the proper things have been targeted and hit.

The best rounds in the list wont mean crap, if all you do is just randomly hit things that wont/dont bring about the necessary damage and destruction to critical parts that actually bring about a quick stop.

If you want to be the least bit realistic here, you have to consider things as a package, and not any one individual thing being the clincher.

Or is this just a paper number crunching exercise and nothing else is being considered?

 

[CDW4ME]

You bring up a good point. Here's another one:

A longer barrel increases velocity. No doubt the vista outdoors testing was done with a 4-4.5" barrel. The Lucky Gunner test was done with (I believe) a 3.5" barrel. If a bullet is pushed faster into gel it can expand more, which can sometime reduce the penetration depth. It can also expand more but then fold back at the edges of the petals due to the extra force applied to it, and still come out with a smaller diameter in some cases.

But your point on gel type is well taken. Though there is one obvious outlier to your conclusion regarding the 50% additional penetration in clear gel. That 147gr 9mm isn't doing that. I also have see a 10mm 200 HST get only 2" difference between gel types. So there's clearly more going on.

However: If the load in the OP, or a similar load, did make the minimum in 10% ballistic gel, the question remains; is it good enough? My guess is that very few people would feel it is.

One outlier and that was still 3'' more penetration in clear gel than manufacturer testing.

Lets check Winchester:
https://winchesterle.com/-/media/Pr...gun-Bullet-Barrier-Testing-Protocol_2016.ashx
Heavy clothing.
9mm 147 Ranger Bonded - 14'' / .58
40 S&W 180 Ranger T series - 12'' / .76

9mm 147 Ranger Bonded in Lucky Gunner Clear gel - 21.5'' / .51
40 S&W 180 Ranger T series in Lucky Gunner Clear gel - 16.2'' / .70

I think this is sufficient (is for me) to show that clear gel tends to have greater penetration than not clear gel.

"Good enough" sounds like a lesser goal than "Best I can do".
Despite being in the FL heat I manage to have at least a Glock 26 on me even when going to the gym.
Other than the gym, I'm in cargo shorts and a shirt and have no trouble concealing a Glock 19 or larger pistol.
My philosophy is try to carry a handgun I'd prefer in hand to defend myself and I do not prefer to carry less than a good 9mm HP and 11 rounds or more capacity.

Others may content themself with "good enough" or "better than nothing" - doesn't affect me. (One person on here is carrying a single action revolver when they have other options)
May as well include "wouldn't want to / nobody volunteer to get shot by it" as a criteria for ammo selection.
Does the ammo penetrate at least 12'' and consistently expand? No, but I wouldn't want to get shot with it. Infallible ammo selection "logic" that is.

 

[Thomas Mayberry]

Be careful, you may be creating dumdum bullets which are regulated and illegal in many areas.

Please enlighten me. Dumdum bullets were addressed in the Hague accords (which also prohibited submarine warfare) but the U.S. was not a signatory to the accords. I'm aware that New Jersey prohibits the carry of hollowpoint ammunition (which a few decades ago anti-gunners called dumdums) outside the home.

Can you identify which states, counties or municipalities prohibit "dumdums"? Outside of NJ I'm unaware of any.

 

[Skribs]

Im beginning to think that people are so hung up on the paper/gel numbers thing, that they have completely missed the reasons why you want power and penetration, and why you want to hit certain things and do so quickly and repetitively so you increase your chances of a good hit in there somewhere amongst all the chaos, and try and bring about a quick resolution to things.

Will that 22mag work? Yes, no, maybe. Where are you shooting them to make it work? Are we saying that a hit "anywhere" is all that's needed to incapacitate? Or are we saying it might, or might not reach a vital organ and do enough damage, to start the process of stopping things? And of course, that assumes the proper things have been targeted and hit.

The best rounds in the list wont mean crap, if all you do is just randomly hit things that wont/dont bring about the necessary damage and destruction to critical parts that actually bring about a quick stop.

If you want to be the least bit realistic here, you have to consider things as a package, and not any one individual thing being the clincher.

Or is this just a paper number crunching exercise and nothing else is being considered?

I mean....yes, most of what you're saying is technically true. But functionally speaking, what's the point of all of this?

Let's say we're comparing 22mag to other handguns, like 9mm or .45 ACP. Are you saying that a 22mag is not going to have the same shot placement as a 9mm or .45? Or are you saying that the 9mm and .45 are more capable in hits where you didn't hit exactly COM?

Are you saying that people either do target practice or gel tests, but not both, and that anyone doing gel tests doesn't know what they're doing?

As to this..."If you want to be the least bit realistic here, you have to consider things as a package, and not any one individual thing being the clincher."

I disagree that you can't evaluate individual parts of the package. In fact, isolating variables it the best way to have conclusive tests. I could do a "package" that's a 9mm +P hydra shock in a 16" carbine and compare it to a .45 ACP round-nose out of a 3" barrel and conclude that 9mm does more damage.

Or I can decide that I want a compact Glock, and then the clincher is the single variable of whether I want a 9mm, .40 S&W, .45 ACP, or any other less-common round.

 

[mavracer]

A clear (pun intended) difference is that clear gel is showing about 50% more penetration (about 6'') than manufacturer data.

Another issue with LuckyGunner results is they shoot all 5 rounds into the same block so many times rounds 3,4 or 5 will skew the average by following the path of one of the previous bullets.

 

[Kleanbore]

We all know (or should), that the basic part of the FBI cartridge qualification tests are that a bullet penetrate between 12" to 18" into ballistic gel through 4 layers of denim, and expand to at least 150% of the bullet's unexpanded diameter. The FBI has additional testing of course, and they use a particular kind of gel that is "calibrated" prior to testing. They also have some other specifics to the testing protocols not commonly spoken of....
Here we have a .22 Magnum load from Hornady, that from a 4.3" KelTec does meet the penetration and expansion requirements (you may have to select the 4.3" barrel in the small drop down menu)...Based on the commonly accepted "truths" about what a handgun bullet can do and what the FBI says is important, is this cartridge not all a person would need?

Is that load, or any other .22 rimfire, among any of the purchase contracts let by the FBI or by Homleand Security for use by non-military Federal agencies? Do you know of any police departments that use it?

 

[sgt127]

I can come up with a test that conclusively proves, one bullet is superior to all others.

Then change a few criteria and make it the worst bullet.

In a perfect world, I want a bullet that fully traverses an opponents body. At any angle. No matter how big they are. After passing through his bicep. The 60 pounds of fat on his gut. Through a leather jacket. And stop, with the tip of the bullet just breaking the skin, on the other side.

Since I may have to shoot a 140 pound cranked up meth head or, a drunk 350 Pound ex con that spent the last 15 years pumping iron, we have a dilemma.

For that reason. I want penetration over everything. And, I’ll take a flat point. Not a lead parachute that I KNOW can’t possibly go deep enough.

If it’s a hollow point, I wanted bonded construction and lots of velocity.

Remember, all premium ammo behaves almost exactly the same. Because they all created ammo to meet the specific FBI requirements.

And, ammo companies want to make money.

 

[fastbolt]

The FBI's original testing protocols were designed to test potential duty ammunition for their needs, as they saw them. When we'd see the test reports, the FBI included a disclaimer that they weren't recommending the selection of any particular ammunition for anyone else, and other LE agencies needed to determine the needs that would satisfy their anticipated requirements. Also, while I was given a thick copy of the early testing back in '90, at a firearm instructor class in which the FBI participated, getting subsequent versions of their testing required requesting it on agency letterhead, signed by a supervisor (or above).

Once the major American ammo makers started using the testing protocols to design and evaluate their ammunition, especially for submitting bids for LE/Gov contracts, the race was on. However, not all JHP ammunition marketed to the civilian/public market was tested using the protocols, or wasn't designed to meet all of them, etc. It was sometimes interesting to look at the commercial marketing for ammunition not designed to meet LE/Gov testing requirements.

Yes, properly prepared, kept chilled and 'calibrated' (penetration tested with BB gun at known velocity) does offer some differences in observed testing scenarios compared to the new synthetic 'clear' blocks being sold. Preparing and using organic gelatin involves more difficulties than the 'out of the box' clear gel products.

The FBI testing protocols use a "Heavy Clothing" barrier test with a specific type of cloth layers. (Hornady lists the FBI protocols, if you're interested.)

The 4 Layers of Denim (again, of a specific type) test came about as the result of the IWBA, and the involvement of a Lt at the CHP academy. It was basically intended to be an engineering 'acid test' for JHP bullets to demonstrate the ability to resist becoming plugged, while still robustly expanding.

Interestingly, the results of the early 4LD testing showed that the recovered test bullets resembled those recovered in some actual shooting incidents. Keep in mind that properly set up and scientifically conducted testing mediums and protocols show the effects of the mediums on the bullets, but can't be expected to predict the way expanded bullets will affect human anatomy in any particular instance.

 

[trackskippy]

I mean....yes, most of what you're saying is technically true. But functionally speaking, what's the point of all of this?

Let's say we're comparing 22mag to other handguns, like 9mm or .45 ACP. Are you saying that a 22mag is not going to have the same shot placement as a 9mm or .45? Or are you saying that the 9mm and .45 are more capable in hits where you didn't hit exactly COM?

Are you saying that people either do target practice or gel tests, but not both, and that anyone doing gel tests doesn't know what they're doing?

As to this..."If you want to be the least bit realistic here, you have to consider things as a package, and not any one individual thing being the clincher."

I disagree that you can't evaluate individual parts of the package. In fact, isolating variables it the best way to have conclusive tests. I could do a "package" that's a 9mm +P hydra shock in a 16" carbine and compare it to a .45 ACP round-nose out of a 3" barrel and conclude that 9mm does more damage.

Or I can decide that I want a compact Glock, and then the clincher is the single variable of whether I want a 9mm, .40 S&W, .45 ACP, or any other less-common round.

What Im getting at is, basically what sgt127 says above.

And the rounds are just one small part of this. You have to make things work with what you have/choose, and thats actually more important than what the rounds are, as regardless, you have to keep doing whatever it takes to solve things, no matter whats in the gun. One may work better than others, in some respects, but regardless of that, your response should always be the same, no matter whats going on with the rounds.

Everyone seems to get so wrapped up in the paper numbers and ballistics of things, and want to base things on that, and what and how someone (whomever that may be) "expects" they will perform and act, when every instance is its own critter, and have no idea as to what you might get. Will they fall down from the crack of a near miss blowing by their head because they "think" they got shot, or will they absorb every round you dumped into them and keep coming?

Having shot a lot of different things, big and small, with all sorts of calibers, I know you can kill pretty much anything, with anything, but the difference between DRT (which I always thought was preferable) and dead a while later (not so much), and maybe not at all, can vary with anything.

Ive shot things with FMJ that were DRT, and Ive shot things with multiple "premium" handgun rounds, that according to the numbers experts, should have been DRT because of "the numbers", and they still scampered or run off.

If you want to argue numbers for the sake of arguing numbers, thats cool I guess, if thats your thing. I just dont think most of whats argued there, really takes into account reality, at least as far as things go when you start shooting things that have too many variables, to give any kind of honest answer. Beyond "maybe" anyway.

 

[Double Naught Spy]

Based on the commonly accepted "truths" about what a handgun bullet can do and what the FBI says is important, is this cartridge not all a person would need?

LOL, when you have standards, there are generally a minimal and maximum standard that is considered (or codified) as such. These mins and maxes are generally the trailing edges of performance and as such may have less applicability in overall use.

When you buy a car, do you buy a car that will go no faster than the minimum speed limit on the highway?

Sure, if you can make a perfect shot when you need to make a perfect shot go with the .22 mag as your caliber that meets the FBI's standards. Otherwise, larger and more powerful calibers would likely do you a better job for self defense.

Strangely, I don't see the FBI chambering .22 mag in their guns. Maybe they don't think the minimums is all that should matter, either.

 

[fastbolt]

You know, whenever some of our people would inevitably ask about why we were using whatever caliber/brand of duty ammunition we were using at the time (and both the calibers and the brands/lines changed at different times), I'd offer a simple perspective.

This is what we're using (issuing and/or approving for optional use). It's a JHP bullet, regardless of caliber or brand. When it comes right down to it, how well can you use it? Also, how well can you make good decisions under stress?

 

[WrongHanded]

Is that load, or any other .22 rimfire, among any of the purchase contracts let by the FBI or by Homleand Security for use by non-military Federal agencies? Do you know of any police departments that use it?

Not that I'm aware of. I'm also not aware of any 10mm or .357 Magnum that currently makes that list. What LE agencies buy or don't isn't the subject of the OP. But then neither is the difference between one kind of gel and another. So I suppose of you want to go down that rabbit hole, do so.

 

[Kleanbore]

What LE agencies buy or don't isn't the subject of the OP.

Perhaps not the way it was phrased, but it would be very germane to the obvious intent.

If no LE agencies use it, why would anyone conclude that it might be "all a person would need"?

 

[WrongHanded]

Perhaps not the way it was phrased, but it would be very germane to the obvious intent.

If no LE agencies use it, why would anyone conclude that it might be "all a person would need"?

So the point of the OP was to get people thinking about how maybe they want more than just penetration and expansion minimums. Some of use choose ammunition based on a wider range of criteria. That criteria may vary from person to person. What law enforcement (local, state, or national) use is one way. The OSS data is another.

But let me answer your question with another question. If only one or two LE agencies use a particular load, does that tell us that load is "all a person would need"?

 

[fastbolt]

FWIW, if the .22WRM were considered an adequate self defense caliber, wouldn't it have been in-service among American LE agencies from the 60's?

Granted, it has been accepted as a secondary (backup) weapon at one time or another. I remember when you could hear of some or other agency issuing the old High Standard Derringer in .22MAG, for example. Even Bill Jordan opined that the .22MAG might make a serviceable hideout gun.

Personally, I see the .22LR/MAG derringers (like the NAA revolvers) being potentially useful as hide-out guns of last resort, like in an Onion Field situation.

I know a friend (another retired peace officer and former firearms trainer) who ended up pulling a .22MAG kit-gun snub one night when he, his wife and a friend were approached by an armed suspect who tried to rob them. The suspect fled before he could get his own gun into position, after he felt the snub's muzzle pushed into his stomach. No shots needed to be fired, and no way he could know it was a .22MAG. I lightly chided my friend for reaching for his .22MAG, instead of the other retirement weapons he was wearing. He sheepishly explained that the .22MAG had been carried so it had been the closest at hand, and said he'd since rearranged the order of the guns he carried, as he'd gotten lazy. (He often carries 2 or 3 retirement weapons. He did 2 tours in SE Asia in the 60's, and spent some time being sent over the borders into a couple countries with whom we weren't at war back then, and still girds himself with a few guns and knives. Old habits, it seems.)

 

[fastbolt]

So the point of the OP was to get people thinking about how maybe they want more than just penetration and expansion minimums. Some of use choose ammunition based on a wider range of criteria. That criteria may vary from person to person. What law enforcement (local, state, or national) use is one way. The OSS data is another. ...

Okay, I'll bite. What other 'wider range of criteria' might someone use to choose defensive handgun ammunition, other than penetration and expansion minimums?

Also, the 'OSS data' is sooo 80's. It's not like it's got any official standing or followers. Interesting to lay shooting enthusiasts, no doubt, but so was the (mythical/hoaxed) Strasbourg Goat Tests.

The lightweight .22MAG bullets lack the mass (and momentum) compared to heavier center-fire defensive/service handgun calibers, including defeating bony structures. That doesn't mean they can't slip between bones and penetrate deeply enough to cause fatal wounding.

If you like to look at OSS-type info, even the 'marginally adequate' pocket pistol .32ACP & .380ACP calibers seem to be 'rated' more effective ... but that may be because they've been used in more incidents.

Another potential disadvantage to the rimfire cartridge is that the priming compound may sometimes not be present all the way around the case rim. Last I read, rimfire cases are spun during the priming stage of manufacture, to try and evenly distribute the priming compound. Center-fire cartridges that use primer cups have become considered more consistent in resulting in ignition. Probably why bigger calibers aren't produced in rimfire configuration anymore.

 

[JohnKSa]

It's enough unless it isn't. An attacker with their arm out in front of them might have the bullet travel up the arm, which could be a lot of penetration before it even gets to the torso. Or, if an attacker is obese or just very large and the angle is bad, it's possible that the bullet might not make it to the vitals.

The bullet that (as far as I can tell) started the FBI penetration standards was the one that hit Platt in the '86 Miami FBI Shootout. If it had hit him directly from the front, it would have exited, or come close to exiting. But it hit him from the side, went through about 4" of upper arm (on an angle) and then into the chest from the side. It penetrated the equivalent of maybe 12" in total, but with 4" of that being in the arm and the bullet having to re-enter the body already expanded, it didn't get to the heart even though it was a fatal shot.

If only one or two LE agencies use a particular load, does that tell us that load is "all a person would need"?

Handgun self-defense is all an odds game.

Most of the time (80%?) a stop is a psychological stop. As far as I know, beyond using expanding ammunition which helps the attacker realize they've been shot, there's not much way to maximize the chances of a psychological stop. It's primarily a matter of probability.

From there, there are probabilities relating to:
1. Hitting/missing.
2. Whether it goes deep enough to hit something vital/incapacitating, even if it hits the attacker and is aimed correctly.
3. Whether it deflects in the body.
4. Whether the bullet expands or hits bone or goes through heavy clothing or an intermediate barrier and doesn't expand well.