Bullets hitting bone?

[CobrayCommando]

I'm curious, what happens when a hard cast lead or full metal jacket hits bone in tissue? Does a spray of white fragments come out the other side? What kind of extra wounding effects, if any, happen when a bullet hits something like the sternum or ribcage?

Thanks all.

[Odd Job]

I can only comment on human targets shot with handguns.
The bone splinters can cause additional damage, almost as secondary projectiles. These can make an exit with the bullet, but generally they stay in the tissues. They can also be used for the forensic determination of the direction of fire. Here is a picture of a guy who was shot in the lower thigh (distal femur, cropped lateral view for you medical folk).



The entrance wound was at marker 1, and there were two exit wounds, marker 2 and 3. Fragments of a bullet are in the leg. The likelihood is that breaches 2 and 3 are due to separate parts of the original bullet having enough energy to make an exit. The evidence is that the guy was shot in the back of the thigh, the bullet broke his femur and pieces of bullet and bone drifted towards the front. Two items made an exit. I say items because it cannot be ruled out that one of the exiting items was a piece of bone. But that degree of bone displacement is not unusual in gunshot wounds involving 'long bones.' There is less resistance from 'flat bones' such as the skull and pelvic crests where the bullet will more likely punch through without making large bone splinters. And then you get the unpredictable 'deflectors' such as teeth, vertebrae and tarsal and carpel bones. Well you could write a whole book on the subject of gunshot wounds

[Twycross]

Since this is the hunting forum, I assume you mean rifle and magnum handgun rounds. If you are lucky, the bone will shatter, and cause secondary damage within the body cavity. The fragments should stay inside, though.

[CobrayCommando]

Perfect, thats just what I was looking for. I chose the hunting forum because I assumed more people here would have experience with bullet hitting bone, so in fact experiences with service caliber handguns and human bone is even better.

Generally speaking when a bullet hits a flat bone such as the sternum, how far do the bone fragments travel? Do they each cut individual holes, or do the holes sort of join up to form a jellified mass in front of the impact?

[Twycross]

Generally speaking when a bullet hits a flat bone such as the sternum, how far do the bone fragments travel?

That will depend on a lot of factors, including the angle and force of the strike, but judging from what I've seen in deer, optimally it could be a good 8-10 inches or more. I don't have any data to support that, just observations.

Do they each cut individual holes, or do the holes sort of join up to form a jellified mass in front of the impact?

Each fragment should have it's own path, but it would be hard to trace them. The only wounds I've seen that involved bone destruction had jelly from the hydrostatic (sp?) shock, so I don't know how much is attributable to the bone fragements. But hydrostatic shock doesn't really exist in most handgun calibers, so the medical types here could help you more.

[Wisby]

I shot my buck this year high and hit him in the backbone. I was shooting downhill and once the bullet struck the Backbone it angle'd straight down poped out his breastbone. The bullet did not exit though. I was shooting a .280 with a 150 grain bullet I believe might have been 160. The backbone was fragmented pretty bad, with lots of bone chips.

[Long Path]

In my experience, bone can make excellent secondary fragments. The problem is, they're quite unpredictable. I've had and seen hits that raked the lower part of the spine throw fragments into the heart (a considerable deflection!).

[#18indycolts]

too bad, thats why we ask these questions, right?

[Odd Job]

Unfortunately the ballistic variables combined with the anatomical variables and added to the clothing and intermediate target variables render it impossible to predict with certainty what the effects will be when a human sternum is shot. One can only offer very general observations based upon X amount of cases. A gunshot sternum isn't a very common sighting in a hospital. In fact I rate it as number 2 on my list of 'hard to come by' bone fractures due to gunshot wounds. Number 1 on my list is the nasal bone. But anyway, I think it is important to realise that no two shootings are ever the same. Sure, there have been many cases of 'long bone' shootings in which a 'characteristic' fracture pattern has been seen, and there have been many cases where the flat bone of the skull vault has been perforated and a 'characteristic' fracture pattern has been seen too. Those injuries are relatively common. We more-or-less know what can happen when those bones are shot. My opinion is that a sternum will not fragment much when shot with a handgun. It is flat and has a lot of support from the anterior costal cartilages and the muscles of the chest. Of course, all these 'opinions' go out the window when you have an unusual trajectory or a variation in the anatomy. But as it stands I can't give you an example of a sternum fracture because of a gunshot wound.
But have a look at this radiograph:



This is a guy who was shot while prone on a bed. He sustained multiple rib fractures (white arrows) but hardly any fragmentation of the bullet occured. The red arrows show lead specks from the bullet. The blue arrows show technical artefacts from a dirty intensifying screen. The cropped image on the right has been sharpened a little so you can make out the fractures a little more easily. Now this may seem like not such a big deal, but this is a classic case of the bullet refusing to read any of the medical or ballistic text books before entering the patient. Those ribs have been hit almost edge-on and yet instead of deflecting anteriorly or posteriorly, the bullet has gone on to fracture 4 ribs in turn. Furthermore the degree of displacement of one fracture relative to another is different in each case. Who could have predicted this? The patient sustained a pneumothorax (collapsed lung for non-medical folk), but it is impossible to tell whether this was because of the passage of the bullet itself or the deflection of sharp rib fragments into the lung. If I was pressed to choose, I would pick the rib fragments. Those are very sharp and surgeons are wary of them!

And one more case (or I'll be told not to turn TFL into a forensic forum ) involves a young man who was shot in the lower leg by a jacketed projectile, probably a 9mm (or thereabouts) FMJ.



Here is a fractured left tibia and fibula (the tibia is the main bone, the thick one that takes all your weight and the thin one is the fibula which is not a big deal if fractured). There is a deformed bullet medially (on the inside of the leg). What's interesting here is that it is very difficult to understand the trajectory in view of the fact that there is an entrance and exit wound, both bones are fractured and the main mass of the bullet remains in the wound. The fracture pattern and displacement of bone fragments from the tibia indicates that the guy was shot from the antero-lateral aspect (from 10 o'clock), and the tibia was fractured first. There was a deflection posteriorly (between 6 and 7 o'clock) which resulted in the fibula being fractured. Then from the fibula the bullet was deflected medially (3 o'clock) and that is where it came to rest. But again, there is no telling whether the exit wound was caused by a piece of bullet (we would call it a daughter fragment) or by a piece of tibia. I say tibia and not fibula because I will go out on a limb and declare that all the pieces of the fibula are still in situ. I guess you could call this a case of ballistic pinball! Gunshots involving bones can be very strange...

By the way, skin breach markers are essential in any kind of analysis of bone fragment displacement in gunshot injuries and I hope you medical folk out there are enforcing this in your hospitals. That first chest case doesn't have any because it is not the initial X-ray series, but initial ones must be marked.

[Long Path]

Great information, Odd Job! As a hunter, a shotist, and student of law enforcement, I find great use in this. I'd like to see more, frankly.

[mete]

All bone is not the same ! A deer leg bone is seven times denser than a cows !Young animals usually have denser bones than older ones .Secondary projectiles can have a great effect on 'performance '. While I had know about secondary projectiles for years , the first ime I had seen it was when butchering a friends deer. He shot it through th shoulders with a 270. When slicing the ham I found a piece of bone that had come from the shoulder and penetrated half way through the thickest part of the ham !!! Higher velocity also works differently than low velocity. My orthopedic surgeon cousin once described a kid that had been hit with a high velocity 22 , the upper arm shattered into about 100 pieces !!

[Twycross]

Wow, Odd Job, this is good stuff!

[fisherman66]

How did all those paperclips end up in the bullet path? Office shooting?

[yorec]

Ditto Oddjob!

Lol - those do look like paperclips, don't they? I suspect there's an explanation though... ?

Bones do strange things to bullets is what I know. Seen many animal wounds where high speed, heavy rounds punch through and do thier work despite hitting bone - but that's the goal of good hunting rounds. But when they don't punch straight through (the round bones Oddjob mentioned) things become a lot more random - and, I suspect, that's more likely to happen with lighter bullets at slower speeds...

I Remember one accidental shooting where a skinny little teenager kid took a .25-06 hunting round to his shoulder across his torso to the other shoulder (came to a rest on the scapula) breaking ribs, collar bones, shoulder blades etc - never heard the total rundown - fragments went everywhere collapsing both lungs, but missing the heart and spine - but he still survived and last I heard should recover pretty well! I thought he was a goner for sure... But there's just no telling what's going to happen when bones get involved.

[Odd Job]

Those are the skin breach markers, applied by the radiographer before doing the X-ray. They provide a radiological reference of the position of surface breaches relative to the internal anatomy. Paperclips are an easy cheap way to do it. They should be opened up into triangles so that the skin breach is in the middle.

[Odd Job]

@ Long Path

Perhaps there is scope for a forensic/medical category? I suspect that we have enough medical and paramedical members to make some worthwhile contributions here? Just a thought.
Otherwise we could have "Odd Job's medical imaging musings" as a veeeeeeeery long thread

[Johnny Guest]

CobrayCommando, thanks for asking the question - - It prompted some interesting information.

Odd Job writes:

And one more case (or I'll be told not to turn TFL into a forensic forum )

and

Perhaps there is scope for a forensic/medical category? I suspect that we have enough medical and paramedical members to make some worthwhile contributions here?

Odd, please don't worry too much about being censured for making these very enlightening entries. Happens I've spent considerable time with both moderators of this forum, Rich and Art, sitting around and discussing terminal bullet performance. I'll make so bold as to say they'll approve, and if not, I'll fade the heat for encouraging you.

It may be there IS a place for such a separate forum. If not, I'm perfectly happy with your observations and illustrations here in Hunting Forum. I cannot picture anyone at all interested in actual hunting - - with it's logical conclusion of drawing blood - - who would be offended by knowledge of what happens when a projectile actually impacts a living target.

I'll look forward to reading/viewing more from you.

All the best,
Johnny

[Odd Job]

All right gents, thanks for the encouragement. I'm open to questions/requests, preferably as regards handgun wounds on humans.

[Greybeard]

Sorry guys, but pixes from disposable camera did not come out well, so you'll just have to bear with my text.

I shot a "management doe" during "extended season" in Runnels County a couple of weeks ago. Scoped Ruger 7 1/2" SBH in .454. Hornady 240 grain XTP. Box sez muzzle velocity of 1900 fps (downgrgraded from prior box which said 2,000 fps!). I was camoed out sitting with my back next to a tree.

The old doe had been coming across an open wheat field straight at me, so I waited until she hesitated and turned mostly broadside about 40 yards out before dropping the hammer. The XTP caught one lung and took out top of heart before exiting near rear of opposite side rib cage.

Entry hole was downright nasty. About an inch and a half diameter where the JHP was evidently still twisting in the hide about the same mili-second that it hit a big front rib head on. Unfortunately, darkness was setting in, others (with no deer) were waiting on me and I did not get to examine more throughly. Exit wound was much smaller - and hardly bled until I got to rolling her around to field dress.

And concidently, despite the hit described above, the doe was far from DRT. She bolted and ran like the wind for a good 60 yards before piling up in a cloud of dust.

[Johnny Guest]

Staffer hat on - -
Yes, when I first read the thread title, it brought to mind the old G. Kooymans song, "The Twilight Zone." And, while 'WAY off topic, it would be understandable to quote a little of that song. But, friends, please do NOT rip off copyright material and quote it without due credit or attribution.

One entry deleted without prejudice.

Johnny

[epr105]

Oddjob,
I see your location is London. Please tell me are people still shooting each other in the gun free UK?
EPR105

[CobrayCommando]

Amazing X-rays and awesome information, thanks Odd Job!

Thanks everybody for contributing. I now know that sternum shots are unlikely to produce large amounts of bone fragmentation when hit by service caliber handgun bullets.

I'm guessing the same holds for rifle bullets... But then again...

[Odd Job]

@ epr105

I see your location is London. Please tell me are people still shooting each other in the gun free UK?

No, my good man, not to that extent any way. All these images are from South Africa, as is my experience. I trained in South Africa and worked three years permanent night duty at the Johannesburg General Hospital at a time when we were getting an average of 150 gunshot victims a month. And just to 'add sauce to the meal' I followed that up with formal research into gunshot wounds in 2002, tracing the victim from the time he was admitted through all the treatment and imaging, surgery (if applicable), recovery of any projectiles (if applicable) and documenting the acute recovery prognosis. That was a sample of 150 patients and required 450 data sheets and resulted in 1600 photographs of wounds, clothing breaches, X-rays/medical imaging and recovered projectiles. That sample is the subject of a book I am writing (almost finished) and so I can't post those pictures here for copyright reasons. But I have 'adequate' experience and imaging from my years before the research. Some of my older articles are on FirearmsID.com if you are interested in the subject of forensics and gunshot wounds.
I hope that puts my contributions on a more solid footing, in your eyes

[Long Path]

Heh. That would likely put your experience with gunshots wounds well in excess of most of the doctors at any major Level I trauma center over here.

[Odd Job]

I must add (to avoid future confusion) that I am not a doctor, I am a radiographer. But as Long Path knows, Johannesburg is definitely the place to see gunshot wounds. Many foreign doctors go down there to get trauma experience and I would like to think that I have bailed most of them out in terms of interpreting imaging in gunshot cases at one time or another. In fact in cases such as those I have posted here, there is a clinical as well as forensic advantage to tracking the path of these projectiles and any bone fragments that may be involved. That's why even the local veteran trauma surgeons will not scoff at the input of an experienced radiographer: they are certainly well respected in the medical field in South Africa. I may post examples of a clinical nature (where the bone fragment/fracture pattern has enabled the radiographer to influence further imaging requests to find an as-yet unseen projectile).