Some Ballistic Talk- split from "carrying pistols outside gate"

[Teeps74]

The use of pistols in combat....has anyone seriously studied that?
The US Army used to arm the tunnel rats with Colt 45's. Confined areas are conducive to pistols as well, but I'm preaching to the choir now.
:blotto:

Kinetically speaking, at close range, a 5.56mm is going straight through a human body (unless hitting bone) without slowing down. It would take a couple of seconds for a fella to know he was hit. At close range, small hole, not dropping the subject, you have a problem in that the subject keeps coming. A larger caliber pistol (like a .45) would make a bigger hole, and have the effect of knocking the target back, producing needed time and space for a shooter to defend him/her self.

Don't get me wrong, 5.56mm is a great round. I would just prefer the option of a larger caliber pistol at close range (2-15m a la a close in meeting of the minds). A 9mm BHP fills that void (still prefer a slightly larger round but meh).

Just my own opinion... That of an ignorant old 031ner.

 

[KevinB]

Teeps74 your 100% wrong about the 5.56m rounds terminal deployment.

 

[Teeps74]

I never meant to imply that one would not kill, nor cause massive amounts of damage with a 5.56mm at close range. However, at close range is there any knock back from 5.56mm?

Further WHAT'S WRONG WITH THE WOUND BALLISTICS LITERATURE, AND WHY From the Letterman Army Institute of Research Division of Military Trauma Research, Presidio of San Francisco:

When a penetrating projectile does cause significant tissue disruption, that disruption is usually very obvious. For example, in an uncomplicated extremity wound caused by the M-16 rifle (Fig 2), if the bullet yaws significantly and fragments, this will be evident in the form of a large exit hole. If no significant yaw occurs, the exit will closely resemble the entrance hole, and little or no functional disturbance will be evident because of minimal tissue disruption. If, on the other hand, the bullet breaks up very early in its path through the tissue, it is possible that the entrance and exit holes could be small despite marked tissue disruption within the limb (such a pattern is typical of a soft point bullet (Fig 7); occasionally this pattern may also be produced by the M-16 bullet. The situation should pose no diagnostic problem; marked functional disturbance with swelling will be obvious on physical examination, and the bullet fragmentation with soft tissue disruption will be obvious on biplanar x-rays. As in the therapy of any other form of trauma, objective data should guide treatment decisions.

There is an assumption that a 5.56mm travelling at above 2,700fps will fragment on entry. What about the exit muzzle velocity of 3,200fps? When travelling at 3,200fps through 50cm of soft tissue, is there time for fragmentation to occur?

Also note, in your diagrams, the "outside bubble" is a temporary cavity, where as the "inside" route is the permanent as demonstrated in this 7.62mm illustration (clearest pic I can find on short notice):

I do not intend to argue that one 5.56mm round at close range would not kill someone. Only that I question whether or not it would knock someone back in a close quarters situation (which I have not been in myself to date). At close range (2-15m), a target coming at me with an axe, grenade or other weapon, I do value knock back as much as kill ability of a projectile. There are instances, at close range, of individuals continuing to advance while being shot at close range.

 

[daftandbarmy]

OK, now you've got me wanting to transfer to something a little less 'infantry'.

 

[zipperhead_cop]

Caveat:  I am no ballistics expert.

From what I have been taught, the idea of "knock back" is a bit of a fallacy.  Think Newtons Laws of Physics.  If the slug had enough kinetic energy to push back a grown man physically, it would need to impart that much energy on the shooter as it left the weapon.  I think that is why we don't shoot the 81mm mortar from the shoulder anymore. 
As for the various rounds, you can get a lot more fragmentation if the slugs are not jacketed, but since we fight our wars with rules, we can't use hollow point or controlled expansion rounds. 
With regards to the BHP, if we were allowed to use something like Winchester Ranger SXT ammo (used to be called Black Talons) you would see a lot more wound characteristics after penetration.  But DumDum rounds are bad, so we have the 9mm ball we have now. 
I-6 do you have one of those wound charts for pistol ammo?  The one I saw like the ones you posted showed most jacketed pistol rounds plow right through and don't start tumbling (hence doing the really brutal damage) until they are out the other side. 

 

[MG34]

Teeps74: There is no such thing as knock back....it is a myth,fallicy,etc when a target is hit by a lethal round it either collapses on the spot or moves under it's own remaining power to die elsewhere.You are watching too many movies.
A 5.56mm round will fragment if travelling over 2700fps regardless of the range,it has to do with the design of the round and it's built in "weakness" at the cannalure, it's tendency to yaw in liquid/soft tissue,and the fact it cannot remain stable in a liquid as it is designed to travel in the air. With the muzzle contact shot as you describe there will also be an introduction of propellant gasses and heat into the wound which will add to the trauma and create an explosive wound profile due to the still expanding gasses.
  The temp cavity illiustration is well known and has also been debunked as a mechanisim of wounding in all but non elastic tissue (eg.brain,liver).
This has been discussed many times here, please do a search in future.

 

[Teeps74]

Interesting thread of thought...

A Beginner's Guide to Stopping Power, By Chuck Hawks posits:

But in terms of the mechanisms of wound dynamics, rifle bullets and pistol bullets are both bullets, and function in pretty much the same way. The stopping power of pistol loads and the killing power of rifle loads are both based on a combination of the temporary stretch cavity and the permanent crush cavity produced by the bullet as it traverses the target. Any theory that ignores either of these factors will give erroneous results. Ignore the temporary stretch cavity and your results will favor big caliber bullets. Ignore the crush cavity and your results will favor high velocity, nearly explosive bullets. Both results will be incorrect.

So, mechanically speaking, will a faster smaller projectile create a larger stretch cavity? (Stretch cavity is almost as good as fragmentation when it comes to killing power).

(Yes, I am trying to draw out a ballistics conversation).

 

[MG34]

Temp cavity/stretch cavity is not significant with relation to the wounding potential or lethality of any round,unless the tissue is non elastic then radial tears may occur. Most organs and blood vessels are simply pushed out of the way of the temp cavity as it forms with none or minimal damage occuring. Read Dr. Martin Fackler he is about the most authoritive SME on the subject, the idea on temp cavity Mr Hawks is  using is wrong, has been proven so for many years now.

 

[KevinB]

I've got a lot of USSOC data - and other stuff.

  The stretch is only good in non elastic tissue -- the temp cavity in a lot of tissue does not cause a great deal of damage (the human is remarkably resilient).


I've never shot anyone yet with a handgun -- one so close but not close enough issue.  But I have utter confidence in my M4 at close range to pretty far...

 

[MG34]

I can say with certainty that a 5.56mm C77 round will fragment  from a C7A2 in soft tissue at a range of  2 feet or so.

The problem with most ballistics data on the net is that it is flawed or dated, concepts such as " knock down power", "killing power",etc are outdated,wrong and show the person using them is either ignorant of the facts or is spouting some crap they read on the "internetz". Good sources are easy to find search for Dr. Martin Fackler,he is about the only SME on the subject that holds any real credibility,the mentioned USSOC data is good if you can find it.

 

[mudgunner49]

I can say with certainty that a 5.56mm C77 round will fragment  from a C7A2 in soft tissue at a range of  2 feet or so.

The problem with most ballistics data on the net is that it is flawed or dated, concepts such as " knock down power", "killing power",etc are outdated,wrong and show the person using them is either ignorant of the facts or is spouting some crap they read on the "internetz". Good sources are easy to find search for Dr. Martin Fackler, or Dr. Gary Roberts, he is about the only SME on the subject that holds any real credibility,the mentioned USSOC data is good if you can find it.

Dude, I fixed your post for you...


blake

 

[KevinB]

Ditto on LCdr Roberts, Gary was Facklers Protoge. 

  He is one of the best current sources (for LE/MIL) of ballistics research.  He is heavily weighted to the 6.8 round - and I beleive some of his conclusions are not 100% correct -- but he is a GREAT source of knowledge.


Second having good result with a Mk18/C8CQB 10" carbine ~400m I can tell you, frag is not the end all be all -- bullet placement bullet placement bullet placement.

 

[Teeps74]

Can anyone argue bullet placement? Learning a lot real fast in this thread...

Question, is there is difference in terminal damage done between a higher velocity smaller bullet (5.56mm) vs a slower velocity larger bullet (9mm)? Looking at the previous charts, they are all in the +2,300 f/s range... 9mm is closer to 1148 f/s if I am not mistaken.

(9mm or 5.56mm... One is still just as dead. Further, for the record, I am a fan of our 5.56mm rd).

I still need to get through this, and have not found an author listed yet (Fackler is referenced throughout though), Terminal Ballistics

In fact the superior stopping power of large bore rounds over smaller faster ones has been well known since the days of the Indian Mutiny,(3) if not earlier. We can make modern medium calibre rounds travel at much higher velocities, but this only seems to increase the temporary cavity, not the permanent one, at least for non-expanding ammunition.

I stumbled across some of the charts earlier... I will try and find them again when I get home (some time tomorrow) and post them up if that is ok... Still hunting for similar charts for pistol rounds.

If nothing else, I am learning a ton in this thread. Another name to look up as a SME I found earlier (courtesy of a wpn tech friend poking at me earlier today) is Charles Fagg.

 

[KevinB]

http://www.firearmstactical.com/wound.htm


Bufford Boone - FBI
and two RCMP Ballitics guys Powley and Dahstrom  (I may have botched the spelling I dont have their stuff in front of me right now)

Those three in addition to Roberts and Fackler are ones you may want to focus on.

 

[MG34]

Dude, I fixed your post for you...


blake

Thanks, was going to bring him up but hit "Post" instead

 

[MG34]

Infidel-6: Big" Roger That" on placement, even the dead go down with a shot to the brain pan.

BTW didn't we have this discussion complete with charts a few months back, and the year before that, and the year before that...etc

 

[mudgunner49]

Infidel-6: Big" Roger That" on placement, even the dead go down with a shot to the brain pan.

BTW didn't we have this discussion complete with charts a few months back, and the year before that, and the year before that...etc

The topic is eternal in it's redundancy.  I guess there are lots of new folks who want to learn old lessons...


blake

 

[KevinB]

Yes -it is a revolving issue, and I know we all seem to get shorter and shorter in our answers...


I am hoping with more and more guys with trigger time -- learning that real life is a mixture of different Holywood shoot reactions, and other than CNS -- nothing is a guarantee -- Hoddie (if he ever posts) and some of the other lurkers can tell about failures to stop with 40mm...

 

[COBRA-6]

Infidel-6: Big" Roger That" on placement, even the undead go down with a shot to the brain pan.

;D

 

[MG34]

Well they are dead after all.