Stopping Power by Caliber Part 2

[LR1955]

Gene,

Danger space is a matter of numbers. Knowing the trajectories, it is easy to determine if one is XX% longer than the other.

But, how can one compare wound profiles and say this one is XX% better than that one. If one wound profile has a 3" neck, and another has a 4" neck, does that mean the former will provide 25% better probability of incapacitation? I think that's very unlikely.

I see no point in arbitrarily specifiying a certain percent of improvement. At this stage, I just want to know what level of improvement can be achieved.

Stan

Stan:

Easy to compare wound cavities in terms of kill / incapacitation capabilities. You compare the amount of tissue damage / temporary and permanent wound cavity and the one with the highest amount of both (combined) has a higher probability of inflicting a wound -- either critical injury or incapacitation. The more tissue your bullet damages in relation to a target the dimensions of an adult upper torso the higher the probability it will damage the heart / lung area and arteries. There is no way around it.

I contend that the technology of small arms is pretty mature with little on the horizon that shows promise of a significant improvement in issued service rifle ammunition. You do not need to explore things that have already matured in terms of technology. You need to start comparing using criteria that you all know as authorities / experts are critical factors or variables. To do so, you must be able to state what represents significance.

What represents a significant increase in wound cavity at 100, 300 and 500 meters?

Oh yes, almost forgot. Why are you trying to use subsonic pistol ammunition as a model to compare with supersonic rifle ammunition?

LR1955

[stanc]

Stan: Easy to compare wound cavities in terms of kill / incapacitation capabilities. You compare the amount of tissue damage / temporary and permanent wound cavity and the one with the highest amount of both (combined) has a higher probability of inflicting a wound...

Gene, I realize that it would have a higher probability. What I'm asking is: How much higher?

You can put a number on the % increase in danger zone, but how do you determine the % increase in lethality or incapacition?

I contend that the technology of small arms is pretty mature with little on the horizon that shows promise of a significant improvement in issued service rifle ammunition.

I'm sure you're right. However, it may be possible to develop an intermediate-caliber round (as per Tony Williams' proposal) that has greater terminal effects than 5.56 M855, combined with the "reach" of 7.62 M80, but with less weight penalty than the latter.

You do not need to explore things that have already matured in terms of technology.

I disagree. There is extremely little data available on terminal performance and barrier penetration of 6.5mm FMJ bullets.

You need to start comparing using criteria that you all know as authorities / experts are critical factors or variables.

Whoa, pardner. I never claimed to be an authority or an expert.

To do so, you must be able to state what represents significance.

Any number that I could place on it would be purely arbitrary. As such, I don't see that it would be worthwhile.

I contend we need to test available, non-deforming 6.5mm FMJ bullets -- the 120gr Norma now, and the 110gr Wolf if/when it arrives -- in order to determine what level of performance can actually be achieved. If such tests showed an improvement, then there would be a factual basis for deciding if it is "significant" or not. Otherwise, it's just pulling numbers out of the air.

What represents a significant increase in wound cavity at 100, 300 and 500 meters?

Beats me. And I don't mean to be flip, it's just that I don't know.

Oh yes, almost forgot. Why are you trying to use subsonic pistol ammunition as a model to compare with supersonic rifle ammunition?

No fair! That was my question.

[JASmith]

...Why are you trying to use subsonic pistol ammunition as a model to compare with supersonic rifle ammunition?...

The 124 grain 9mm M882 bullet has a muzzle velocity of 1263 ft/sec.

Technically it's on the high end of transonic but definitely going faster than the speed of sound in most parts of the world. For example, at 90F the speed of sound is close to 1150, it doesn't creep up to 1200 until the air temperature reaches 140F -- not many places are that hot.

In any event, the operative issue is not the speed of sound in air, but in things like the watery bag that makes up most of the body. This number is more like 5000 ft/sec...

To be sure, a shock wave races out ahead of the bullet, but it's intensity is not enough to cause damage. Consider the sonic destruction of kidney stones.

[LR1955]

The 124 grain 9mm M882 bullet has a muzzle velocity of 1263 ft/sec.

Technically it's on the high end of transonic but definitely going faster than the speed of sound in most parts of the world. For example, at 90F the speed of sound is close to 1150, it doesn't creep up to 1200 until the air temperature reaches 140F -- not many places are that hot.

In any event, the operative issue is not the speed of sound in air, but in things like the watery bag that makes up most of the body. This number is more like 5000 ft/sec...

To be sure, a shock wave races out ahead of the bullet, but it's intensity is not enough to cause damage. Consider the sonic destruction of kidney stones.

Joe:

So, what happens to that water when a bullet goes through it at say 2000 feet per second as opposed to say 800 feet per second?

LR55

[JASmith]

The faster bullet makes a tad larger splash.

[LR1955]

The faster bullet makes a tad larger splash.

Joe:

Interesting comment so I have to ask.

What is your opinion on hydrostatic shock as a means of inflicting a wound?

I ask because some do not believe it plays a role at all and others believes it plays the only role. I contend it does play a major role with supersonic rifle ammunition but very little role with subsonic pistol ammunition.

Oh yes, that 9mm service round may have a statistical MV of 1200 fps from an M-9 but my bet is that by the time it goes ten or fifteen feet is is well below that level. And even if it hits someone at that level, it will be below the same once it passes through clothing and skin.

LR1955

[JASmith]

...What is your opinion on hydrostatic shock as a means of inflicting a wound?...

Gene,

I had believed that hydrostatic shock was very important from the late '50s when I read the reports of how devastating the .17 caliber rifles were on feral burros in the Southwest. Comments like "the blood coming out as a single organ" during the skinning and butchering were rather convincing.

After reading Fackler's and others' reports, I have come to realize that hydrostatic shock was not the source of the injuries. The massive internal bleeding was most likely caused by massive fragmentation of the small projectile probably coupled with secondary fragments from bone impact.

Consider a broadhead hunting arrow -- game seems to go down as quickly when properly hit just the same as with hunting bullets. How much hydrostatic shock does the arrow produce?

...a major role with supersonic rifle ammunition but very little role with subsonic pistol ammunition...

I made the earlier comment about breaking kidney stone using sonic pulses because they are described as being significantly more intense than the shock waves generated by bullets.

One of my favorite pastimes is busting water-filled containers (don't get a lot of hunting opportunities these days). I've noticed that 6 oz through 1 gallon containers show nice violent disruptions when hit by .308/30-06/7.62X54R rounds - the 5.56 is a little less vigorous on the 1 gallon containers but do well on 2-quart items. Five gallon and larger containers just seem to grunt when hit by the 30-caliber bullets even though the bullets cut multiple holes in the container allowing the water to drain. These observations combined with discussions here and reading of critiques of high-speed film "documentation" hyping the dynamic cavity and hydrostatic shock leads me to some conclusions about the dynamic cavity.

1. These critiques suggest that the dynamic cavity is not particularly important for hits on the torso. (Hits on extremities are a different matter, I think.)
   
2. The critical literature doesn't go far enough to explain what's happening (e. g. why do prairie dogs and other small animals seem to explode when hit by high velocity rounds?
   
3. The size of the fluid-filled object matters. Whenever the dynamic cavity is large enough to cause the container to split, it comes apart nicely. The smaller containers show more spectacular results.
   
4. The squirrel and prairie dog have volumes under about 2-quarts while the targets in our discussion are more like 10 gallons when one subtracts the volume of extremities from the 15-20 gallon volume of a 150 lb individual, so we can readily visualize the analogy.
   
5. The relevant damage to living targets with 5-gallon and larger is almost all a result of cutting and tearing by the bullet, fragments, or secondary bone fragments.
   

So, the conclusion appears to be that the supersonic (in air only) rifle bullet brings more mass to the problem and enough energy to cause lots of primary and secondary fragments. The cutting and tearing caused by these is what does the damage...

Cheers!
Joe

[noone]

Gene,

The cutting and tearing caused by these is what does the damage...
Cheers!
Joe

This was the same conclusion reached by the FBI when they did the extensive research after agents got into that shootout with two fellows down south.

The FBI research says that bullets work by causing massive nerve and tissue damage, crushing bones, and causing bleeding.
There is NO magic bullet. All bullets work by the same mechanism...making holes for things to bleed out of, and causing muscle, bone, and nerve damage. The faster this damage is done, the faster the target will succumb.

It doesn't matter if this damage is done by one huge projectile, or by many smaller ones...the mechanism is still the same.

[LRRPF52]

This should really be called, Stopping Power, by Caliber of Willpower to do Violence in the Combatant.

[SIZE="4"]VERY GRAPHIC!! Not for Family viewing![/SIZE]

http://watchevansville.com/play/News_and...phic_Video

Notice how the officer was not willing to use deadly force when it was justified very early in this encounter. His panicked, shrill voice communicated to Brennan that he was scared. That's a big mistake when dealing with someone who is willing to use extreme violence and has experience doing it. Also notice who was willing to close the engagement distance, and eliminate the "threat". You can see when Deputy Dinkheller shot Andrew Brannan in the gut, which was of limited effectiveness, and was followed by Brannan making a final headshot on the Deputy.

The last sounds you hear are the Deputy's gurgled agonal breathing, which is often the body's response when a trauma patient has gone unconscious, and is trying to distribute oxygen, or the heart is not regulated by the normal signals from the central nervous system after a major head injury. I've seen it several times in my life, and you know that the person is in bad shape when you see it.

This video is used in many BLET and other initial entry training for police officers, to demonstrate some do's and don'ts when making traffic stops, talking to motorists, managing the situation, and the escalation of violence. I believe that both combatants executed mag changes or cleared a malfunction during this incident, as you can hear Deputy Dinkheller making his mag change, at which time Brannan closes on him on the right side of the officer's vehicle, then either clears a malfunction or changes mags himself on his M1 Carbine. Upon close examination, it appears to me that Brennan had two 15rd M1 Carbine mags attached together upside down. This makes more sense as they both ran dry about the same time.

If one would want to focus on the tools factor in this incident, I think magazine capacity would be a better place to focus than caliber, although the .30 Carbine penetrates better and from a shoulder-fired weapon, brings more practical accuracy into the fight. At the end of the day, this encounter was unfortunately resolved by the offender, who was willing to close with and destroy his "enemy".

I feel for the officer's family, which included a wife and a baby on the way, I believe. Brennan was found later hiding in the woods under a camo tarp, arrested, and sentenced to death, despite an insanity plea.

I imagine that Platt was behaving in a similar manner in Miami, only with multiple effective shots placed all over his body. There's another video I found yesterday that shows a much better example of how officers can resolve a violent and armed motorist. I'll look for it again and post when I find it.

LRRPF52

[mtn_shooter]

I think the basis for effective stopping power (killing) is a round that is powerful enough to get through common barriers (cars, various types of walls, soft body armor etc..), and still be able to penetrate through most of the body of whatever you're shooting at. At the same time, it can't be so dedicated to armor penetration that it just punches tiny holes in soft targets. Bullet construction is key, IMO. I tend to stray away from anything smaller than 6mm because small light bullets shed energy too quickly for my liking. On the other hand, if you go above about .40 cal, the wide, rounded bullets don't penetrate so well, and you have to increase weight (decrease velocity in standard sized cartridges) significantly to get anything out of them.

With that said, rounds like the 7.62x39mm, 7.92x33mm, 6.5 grendel, .280 british etc. are all good to go in my book for "assault" rifle rounds. The 5.56 in my opinion is on the weaker end of the spectrum, and while it does do the job, I feel other rounds do it better. 6-7.5mm is my personal ideal range for rifle rounds. For pistols, I prefer big and heavy bullets if they have to be slow. 40, 45, 10mm.

I also agree 100% with what LRRPF52 has said. As a USMC 0311 cross trained in physical security (share many police tactics), we're on about the same page. As soon as that guy's rifle broke the plane of the doorway he should have been done. Hell before that, as soon as he charged the police officer he should have been OC'd and cuffed. Actively resistant subjects are not who you want to let do what they want to do-- while watching that video I immediately picked up on the Deputy's voice pitch change and defensive behavior. When people try to get dominant to you, you have to get real mean real quick. Speed, surprise and violence of action is what we're taught. And even since boot camp "Mission of the Marine Corps rifle squad: To locate, close with, and DESTROY the enemy by fire and maneuver, or to repel the enemy's assault by fire and close combat!". As long as you have a weapon that is capable (semi-auto preferably, with a decent caliber, atleast 20 round mags) and the right mindset and training, that's emensely more important than minor caliber variations.

[LRRPF52]

I think that situation could have been calmed a little better from the start, but the Deputy was well-within his right to ask the guy to remove his hands from his pockets. I can tell you that ordering him to put the gun down would not be on my to-do list, as he would have become a bullet magnet at that point until fully-ventilated.

As far as officer survival goes, mag capacity could have yielded a different outcome in that situation, but the willingness to close with and destroy ultimately ended the fight. That is not taught in many civilian circles that I know of, and is bread and butter for 0311's and 11B's.

Sorry I didn't mark the link as graphic. That was an oversight on my part, and I hope no children were traumatized as a result.

LRRPF52

[bwaites]

I think that situation could have been calmed a little better from the start, but the Deputy was well-within his right to ask the guy to remove his hands from his pockets. I can tell you that ordering him to put the gun down would not be on my to-do list, as he would have become a bullet magnet at that point until fully-ventilated.

As far as officer survival goes, mag capacity could have yielded a different outcome in that situation, but the willingness to close with and destroy ultimately ended the fight. That is not taught in many civilian circles that I know of, and is bread and butter for 0311's and 11B's.

Sorry I didn't mark the link as graphic. That was an oversight on my part, and I hope no children were traumatized as a result.

LRRPF52

No problem. The officer seriously made a mistake, asking someone to put a gun down that is swinging towards you is far too late. He should have been firing at that point. But its a knife edge issue for police officers. I don't know if you followed the Utah case of the officer that shot at the suspect driving at him, but the DA has decided that he used unnecessary force, so sometimes the LEO's are screwed regardless of what they do!

Bill

[RangerRick]

Joe:

Oh yes, that 9mm service round may have a statistical MV of 1200 fps from an M-9 but my bet is that by the time it goes ten or fifteen feet is is well below that level. And even if it hits someone at that level, it will be below the same once it passes through clothing and skin.

LR1955

I can tell you from personal experience that clothing slows shrapnel down. It's not a bullet but the shrapnel I got hit with was the filler of an anti personnel mine. It consists of a steel rod cut into short pieces at an angle to create sharp points on both ends. It's about the size and weight of a bullet.

Even though it isn spinning, air resistance causes it to orient one or the other pointy end first over short distances. I had very few oblong holes in me.

When the docs gave me a jar of souvenirs from the surgery, I was surprised to see so much cloth in the jar with it.

They took strips of my outer uniform and my tee shirt into the wound with them. That's got to use up a lot of energy

Any of you guys who have been shot found this to be true too?

[LRRPF52]

Yup, LEO's do have to walk a very fine line, and rightfully so...rules of a civilized society. A second can mean the difference between unnecessary use of deadly force, and your life, which is why I couldn't do that job. Too many people would complain about me exiting the cruiser with an AR15 SBR slung for traffic stops, but I would want nothing less if it turned out to be a carload of narco-traffickers. They will not hesitate one second to shoot you in the face and then bolt.

When watching the video, at the point you realize things are really going south, do you notice how even your own body reacts to the events in the situation? Notice the adrenalin dump and endorphin surge, as well as the stinging tightness on your skin? Those are elements missing from 99% of the firearms and martial training for professionals. Just doing PT or stressful physical exercises is not enough to deposit that component into the equation. True fear...

LRRPF52

[LRRPF52]

I can tell you from personal experience that clothing slows shrapnel down. It's not a bullet but the shrapnel I got hit with was the filler of an anti personnel mine. It consists of a steel rod cut into short pieces at an angle to create sharp points on both ends. It's about the size and weight of a bullet.

Even though it isn spinning, air resistance causes it to orient one or the other pointy end first over short distances. I had very few oblong holes in me.

When the docs gave me a jar of souvenirs from the surgery, I was surprised to see so much cloth in the jar with it.

They took strips of my outer uniform and my tee shirt into the wound with them. That's got to use up a lot of energy

Any of you guys who have been shot found this to be true too?

I took a 9mm through-and-through. It was an FMJ, and was very clean. The wounds bled like drinking fountain faucets, but you can bleed like that for a long time and still be ok for the time it takes to win a gunfight. Fortunately for me, it was an accidental shooting, so I didn't have to beat anyone's face in at the time. I also have the projectile, and it has a flattened dent running diagonally off to the side of the bullet tip, from where it hit the lateral epicondyle of my right femur.

The grenade fragments I've been hit with burned right through my BDU's both times, and kept burning in my skin. I never sought medical care for them as the first was easily picked out with my hand (burned the tips of my fingers slightly), and the second probably worked itself out of my back (did something stupid on a grenade range and didn't want to face possible UCMJ).

Most FMJ wounds are pretty clean, except for 5.56 in my experience. If a round skips through ground debris into a person, there are sometimes rocks in the injured area as well. I've seen that.

If you do get any fabric and foreign debris into a wound, the debris needs to be removed ASAP. This is where debridement comes into play. Basically, you need to expose the wound, irrigate with saline solution, probably open/remove damaged fascia at the entrance/exit, and run gauze through it until the wound path is cleaned. They did that on my legs with the GSW. If you don't debride, the dead tissue and foreign debris will induce infection really quick, and then the muscle tissue will turn black, while skin turns dark and mushy, with no more nerve function, and will need to be removed. This is why mine injures are so effective when a soldier is wounded because he needs to be rushed through the echelons of care from the front to the rear ASAP.

With mine and explosively-launched fragments, you're looking at brissance velocities that start out at up to 34,000 fps if C4 is used, and well over 20,000 fps if TNT is uses. COMP B is closer to C4 IIRC, so explosively-launched projectiles will be going as fast as the atmospheric threshold will tolerate, and they are extremely hot from the initial explosion and air resistance. Bad ju-ju

LRRPF52

[LRRPF52]

To clarify, the explosive velocities are in reference to the heated gaseous expansion of the explosive reaction, while solid projectiles are limited to much slower velocities due to wind resistance and atmospheric pressure. I did read an interesting article in Small Arms Review that discussed how some of the most famous living small arms designers are just learning that lead-core projectiles morph into a plasma state when chamber pressure and heat are exerted on them. They said this accounts for much more barrel heating than they originally thought, combined with friction of the lead pushing outwards from within the confines of the projectile jacket. Adds a whole new understanding to the term..."hot lead".

[RangerRick]

If you do get any fabric and foreign debris into a wound, the debris needs to be removed ASAP. This is where debridement comes into play. Basically, you need to expose the wound, irrigate with saline solution, probably open/remove damaged fascia at the entrance/exit, and run gauze through it until the wound path is cleaned. They did that on my legs with the GSW. If you don't debride, the dead tissue and foreign debris will induce infection really quick, and then the muscle tissue will turn black, while skin turns dark and mushy, with no more nerve function, and will need to be removed. This is why mine injures are so effective when a soldier is wounded because he needs to be rushed through the echelons of care from the front to the rear ASAP.

LRRPF52

Yeah, in my case they stopped the bleeding and left the wounds open for about 10 days, a trick they learned in Vietnam. No sense stitching infection in. They changed my dressings every other day and just spackled Betadine paste into the wound holes with a tongue depressor. Then another trip to the OR for 300+ stitches and skin grafts.

I don't know what the relative speed of the shrapnel was but I suspect it was pretty slow. I was 10 or 15 feet from the blast. So I wonder if a slower or faster projectile would have a tendency to take cloth with with it rather than punching a clean hole in the cloth.

[LRRPF52]

Yeah, in my case they stopped the bleeding and left the wounds open for about 10 days, a trick they learned in Vietnam. No sense stitching infection in. They changed my dressings every other day and just spackled Betadine paste into the wound holes with a tongue depressor. Then another trip to the OR for 300+ stitches and skin grafts.

I don't know what the relative speed of the shrapnel was but I suspect it was pretty slow. I was 10 or 15 feet from the blast. So I wonder if a slower or faster projectile would have a tendency to take cloth with with it rather than punching a clean hole in the cloth.

When you have large wounds, especially traumatic or surgical amputations, it is smart to clean the wounds like that, and do a 10-day delayed primary closure as you described. I saw a pretty good video on this with a mine victim from Afghanistan in the 1990's. His legs were totally intact, but perforated with dozens of small serrated wire fragments from an AP mine. Both his legs were amputated in the video with interlocking "U" cuts, his femurs filed down so they wouldn't lacerate the internal tissues after closure, and he was given the same delayed primary closure protocol you got for 10 days.

The "U" flaps were then sutured together, and prosthetics fit to him. Had he received immediate attention for the small wounds, with a strong antibiotic drip and cleaning of the individual wounds, he would have likely retained his legs with no serious limitations on function, unless his joints were perforated.

The key thing with perforating injuries is proper medical care ASAP. The longer you delay, the sooner infection sets in, and then anything can happen.

LRRPF52

[warped]

Supposedly the slower fragments takes more cloth and other crap into the wound cavity, nasty stuff, consider using the civil war as an example.

[QuadCam]

10-4 on that Vascar! Unfortunately, carrying a shotgun into the movie theater tends to get people a little riled up!

lol.... i'm trying to visualize tha one!