T Nation

Terminal Ballistics


#1

I owe Cephalic_Carnage an apology for the delay in posting this thread. He did the work to track down these links, the delay is non me.

The majority of these links come from the M4carbine website where Dr. Roberts maintains/frequents a forum.

This is an intro to the subject and explains some of the fundamental ideas about what happens when projectiles strike flesh.
http://www.m4carbine.net/showthread.php?t=34714

At this point the use of ballistics gelatin is ubiquitous in testing/proving/or designing ammunition. The gel was developed to be REPEATABLE. Just the same as car crash tests eliminate variables gel is a useful MODEL. It is not and never was intended to be a complete duplicate of the human body.

This link explains what to look at when you see a picture of a gel test.
http://www.m4carbine.net/showthread.php?t=22323

This page provides a variety of sources and links for further study:
http://www.firearmstactical.com/wound.htm

Copy of the FBI "handgun wounding factors and effectiveness" document.
http://www.firearmstactical.com/hwfe.htm

EDIT: on 3/8/12
Open source document on development of 6.8 SPC
http://www.dtic.mil/ndia/2008Intl/Roberts.pdf

Regards,

Robert A


#2

Robert, do you have a link to the full FBI report on the miami shooting by any chance? I'm sure there are a bunch in the terminal ballistics forum of m4c, but I'll be damned if I can remember where...

It's one of the most recognised, studied and ultimately influential cases in regards to terminal ballistics that the analysis on it is pretty much required reading imo and will help many understand where the current ammunition standards come from, what drove much of the improvement seen in the primary duty caliber loads in the last 20+ years, and why we see (or are supposed to see) a greater availablility of patrol carbines and shotguns for LE people.

Also why SMG's have been phased out more and more in favor of carbines/SBR's for CQB work.


#3

No need to apologize, I didn't pay you enough to warrant instant gratification :wink:


#4

Directly from the FBI:

http://vault.fbi.gov/FBI%20Miami%20Shooting%204-11-86%20/

For anyone interested in the miami incident.

Edit: looks like I can post links as long as they don't go to other forums...


#5

Forensic analysis of the miami shooting... Well worth the read imo...


#6

So C-C what do you carry? Or I guess recommend, if you can't carry.


#7

What, handgun, rifle, both?

Back in the day I had no choice what to carry fwiw...

While this is supposed to be a thread about terminal ballistics, considering that we don't have any other gun threads in the combat forum, I'll pose this question here (if we get a lot of discussion going in this thread, we could make a new one on gun prefernces, that's actually another topic I've always been quite interested in as it seems that many select their carry guns based on completely different criteria than I do):

For those of you with access to shotguns on duty or at home... How come so many (private or departments) choose a pump action over semi?
I mean, you can get a saiga or a saiga knockoff or some such legally in several states in the U.S. for not too much money, right?

I've never handled one outside the range but if I had to use one for any reason I'd really feel more comfortable being able to do quick follow up shots with a minimum of arm/hand movement... I get through the shoothouse faster with them, too, vs. a pump action.

Is there a specific reason so few go with that for home-defense? LE I could understand political bs coming into play (oh, look, an even more brutal shotgun blahblah how inhumane), but HD? Afraid of how a jury would react or is there a technical issue or maybe just that fewer people know about them?


#8

C_C - There are several reasons pump guns are used by US police. At first they were getting them from the military as surplus, it was a cost issue. A used Mossberg 500 cost them about 10% of what a new semi-auto would, by the crate and direct from the government. Then, as shotguns became common, specialty rounds such as beanbags and CS Gas were developed, and many of these rounds won't feed in a semi-auto (the reason the USMC, who went to the Benelli M4, kept Mossbergs for their MP's). The Mossberg and the Remington 870 are the two common pump guns, generally because they are fairly reliable, cheap, and marketed well by their respective companies.

The Saiga might work well, but there are no companies bidding to supply 500+ of them on contract that are able and willing to meet all the testing requirements that inevitably come with such contracts. Benelli might be able to, but their guns are more expensive than many departments are willing to pony up, and any imported gun has to fight the "our weapons have to be made here" mentality that prevails in most departments.

Finally there is the perception, if not the reality, that pump guns are more reliable. In my armory experience the gas system is no more likely to fail than the pump system, or at least not so much more that anyone would notice, so this is more of a myth than a fact. I only have experience with the Benelli M4's, Remington 870's, and Mossberg 500's though, so it may be that high-end gas systems fail less but that cheap semi-autos break more frequently than cheap pump guns.

Edit: I re-read that, and you asked about home defense. I think it's generally familiarity and cost, and maybe the perception that the pump gun is more reliable. I like the M4, but the 870 is almost as fast on follow-up with practice and I find that I can hot-load it faster than the M4 (again, not by much).


#9

Thanks, I didn't even consider the specialty LE ammo... Sometimes I forget that you don't always want to kill them...

If I may ask, you ever use a bean bag on someone or see it happen?

I've seen people completely fail to notice eventually fatal hits from 7.62N as well as WP, I'd be scared of having to rely on bean bags... How's that work on guys on drugs or just axe-crazy?


#10

Anybody finding themselves with a bit of time on their hands, be sure to read through the stickies posted in the m4c terminal ballistics subforum... They're all by Doctor Roberts from what I remember, one of the best in the field when it comes to properly done research.

There is an article on duty handgun and caliber choices there which is quite interesting (several posts actually).


#11

Shotguns have major advantages in cost and availability.

$500 will get a truly first rate pump gun, 870P or 590. $250-300 will get a completely serviceable gun (870 express or regular 500). If there is a used rack in the gun store less than $200 dollars can get you armed.

Online decent off-brand AR's cost $800. In a gun shop most are north of $1000.

If you need to arm more than one person the cost difference is magnified. Even if there is money for an AR the cost advantage of the shotgun can be used for more practice ammo or professional training.

Shotguns can be found in many stores that don't sell evil black rifles.

It is easy to buy buckshot or slugs for a 12 gauge. Either are very effective at close range on non armored people. It is very difficult to find any of the "approved" ammo in 5.56 locally.

The shotgun may also shine in two situational areas (may or may not apply):

1.) Ammo flexibility: If you need something to defend against dangerous animals slugs work quite well. I would not want an AR against a bear or bobcat. Birdshot can dispatch small/nuisance animals. Buckshot is great out to 20 yards or so. Slugs do better against car bodies/windshields than most every .233/5.56 load.

2.)Familiarity: If someone grew up running a pump gun it is quite possible that they are far better armed with a 12 gauge than an AR-15.

That said a carbine, such as an AR-15, is going to have massive advantages in capacity, recoil, range, etc.

Regards,

Robert A


#12

Cool. I had a fairly long post about the FBI/Miami shooting that was either nuked by the mods or otherwise vanished. So, maybe I caught what you had. I am assuming that if it was deleted with cause I would get a warning/notice.

Regards,

Robert A


#13

Oh, I meant semi auto shotguns (saiga for example as a relatively cheap one that seems to work well, but you get plenty of others of course) vs. pump action, not shotguns in general vs. assault rifles.

Good points though!

I did not know that ammo which meets the FBI standards is difficult to come by locally in the U.S. for the 556, that sort of surprises me... Seems that if they did their marketing right, companies could sell a good amount as self-defense loads and then go with the cheaper stuff as training ammo...


#14

Maybe just a timeout...

Smaller posts may work... I can't think of any reason why discussing 1986 would be a problem, so it was probably some bug or something...

Any particular thoughts on the miami incident you wanted to share?


#15

Jim, there is a link to gel shots with 380 in there somewhere, but my browser does not want to view the particular link for some reason... Maybe you'll have better luck.

http://ammo.ar15.com/project/Self_Defense_Ammo_FAQ/index.htm

Have not really reviewed the article in detail, though it looks solid on the first quick look.

Will go through it in detail later, as well as the links you posted elsewhere.


#16

.380 ACP testing

Against gel and bone simulant
http://www.brassfetcher.com/380ACP%20JHP%20Bone%20Simulant%20and%20Ballistic%20Gelatin%20Test%20Report.pdf

Page with other test links for .380 ammo.
http://www.brassfetcher.com/index_files/Page638.htm

Regards,

Robert A

EDTA: Consider muzzle velocity with any of this testing.

For 9mm the standard results seem to hold down to 3.5 in barrels.

For .38 special there is a massive difference between snubbie's and 4 in barrels.

For .45 what is fantastic out of a Gov model may fail to expand out of a commander or officer's length barrel (4 and 3inches)

There are a ton of .380's out there. Ammo that may work well out of a Walther PP may not expand out of a Kel tec or a Ruger LCP.


#17

I dimly remember reading someone reputable say something about the bone simulant used in the brassfetcher tests to behave differently from actual bone /vs. autopsy results or something along those lines, don't remember where...

And yeah, barrel length is an important consideration... Also goes for 5.56.


#18

We weren't issued beanbags, so I've never seen one firsthand. The police department near where I grew up used them on suicide threats on the bridge out of town, but as I understand them the primary purpose is riot use. A line of cops fires beanbags into a crowd from behind a shield line, suddenly no one wants to be there anymore and you don't have nearly as many bodies to explain on the news as you would if they used 00 buck. I prefer John Cooper's solution: a suppressed .22 shot to the lungs of whomever is inciting rioters. No one knows what happened, he just finds it very hard to yell all of a sudden. Not sure how well it actually works, but I like the concept. Maybe just use a .308 and get it over with?

Around me the big box stores only sell the "hunting" calibers in any quantity. 30-30 and 30-06 are easy to come by, as is low-grade .308, but some areas are shotgun-only for hunters and their stores reflect that. 5.56/.223 Rem can be had, but with two wars going on the majority of it was overpriced. Lake City can sell their cheap stuff to the government for more than any of us is willing to pay even for Black Hills Gold.

I've never been a reloader, but I may get into it if ammo prices get much worse. It used to be about $0.85/shot for factory match ammo, now it's more like $1.25 and rising. And I don't shoot the exotics, the strangest caliber I've even considered is .260 Remington (Now up to $1.75/shot using the Black Hills Gold 120 gr Hornady GMX, a little less for the 129 gr Remington Cor-bon performance).


#19

Are you calling him "John" because you knew him? Is it the Marine thing? Just wondering.

John Dean Cooper, Lt. Colonel U.S. Marines ret. is usually ID'd as Jeff Cooper or Colonel Cooper in every reference I have seen. Hell, the books I have of his use Jeff Cooper.

As for the solution. I believe it was to target the clear violent instigators who where pushing the crowd towards violence. Sort of a preemptive action before a bunch of blood gets shed. Cooper had experience/communications with a lot of people dealing with civil unrest on a huge scale, like Rhodesia. It is an interesting thought exercise, but I think it is at serious odds with our constitution. I also think that it would ultimately put the police in a bad position.

Regards,

Robert A


#20

couple other reasons.

First is that in the event of a jam, or a failure to fire, it is much easier, quicker, and more natural to re-rack a pump than a semi auto. It may not be more likely that a semi-auto fails, but for many failures, a pump is quicker and easier to deal with when it does.

Second, whether it makes a real difference or not, is that people buy the pump for the sound it makes. Thinking that racking the pump shotgun in the dark will make any would be attacker high tail it out of there.