Factoring bone into the equation

[calvin118]

Hello all,

I am a physician (anesthesiologist) who works at a major metropolitan trauma center. I see a lot of gsw trauma, and although I do not directly perform the surgery it is my job to closely follow and respond to what is happening on the other side of the curtain. My experiences have raised a few questions that I wanted to share.

I have reviewed a lot of the ballistic gel data linked from this and other sites, yet am still a bit confused about the role that bone plays in the equation. Like many of you, I have read the Canadian govt study in which they placed porcine ribs in ballistic gelatin and the ribs did not seem to be much of an impediment. I have serious questions about their methodology, though. Old, presumably dry bones from dead animals have very different physical properties than living, hydrated bones.

DocGKR referenced a study by a Dr. Lane done in 1993 for the FBI. I could not find it myself, and thus have no understanding of the methods. I did, however, come away from DocGKR's statement under the impression that anything smaller than a .40 might not reliably pass through a porcine femur.

In my own limited experience, I have seen a number of xrays in which a femur, pelvis, or vertebral body *appeared* to have stopped what *appeared* to be (judging by the shape) a 9mm fmj bullet. On the other hand, I have seen the humerus, tibia, etc. shattered by projectiles that passed out the other end of the limb and into obscurity. Additionally, I have seen instances of bullets deflecting. Just last week a man attempted suicide with a .38. He shot himself slightly off midline at approximately a T6 level, and the bullet apparently ricocheted and traveled downwards through the abdomen and punctured several loops of bowel.

I have also heard and read a lot of *anecdotes* about 9mm and smaller rounds deflecting off bone (such as the rib in the Miami shootout).

To me, this seems like a huge x-factor. Has anything else been done to assess the effect of bone on terminal ballistics? Will a long bone reliably stop a 9mm, or was what I saw merely a small and biased sampling? Will the sternum or ribs of a large man reliably slow down or deflect smaller rounds? Is/was this only an issue with the older bullet designs weighing less than 124 grains and without +p? Is deflection all about the weight of the bullet, or is the shape important as well (e.g. is the short, blunt nosed .40 less likely to deflect at a less-than-head-on angle than the more conical 9mm at a similar weight)?Is the risk of deflection also present with windshields, heavy clothing, etc. etc. with less than perfectly head-on collisions? Is a differential response to bone a limitation of the gelatin model in comparing different calibers?

Thank you all in advance for your help,
-Calvin

[Odd Job]

There is probably not enough data out there with regards to specific weights and calibres as regards bone fractures. However 9x19 is the most popular carry caliber by far in South Africa and it is what I have seen most often in the theatre recovery jars.

My take on this is that 9mm is just fine for breaking bones. A lot of smaller calibres have done it in unexpected circumstances also, the most noticeable of which was a .25 (or thereabouts) that went through a guy's hand and his thigh, fracturing the thumb and also the femur.

Sure, I have seen FMJs pancaked up against the femur, but I've also seen them go right through, with nary a concern for any bone in between (or apparently so).

But where we stand right now, I don't think we can answer your questions with actual shooting data because we can't get consistency in the data. We can't replicate the shots when comparing one calibre to another. The slightest difference in impact position or angle of incidence could mean that a whole different architecture of the bone is involved. That affects the likelihood of deflection and the amount of cortex that is potentially in the trajectory.

What about bone mineralisation differences, or miscellaneous pathologies that could affect the structure and density of the bone?

I'm am aware of some studies with bone simulant, but I haven't looked into those with enough care to come to an opinion whether they would have merit in answering your questions.

I must state for the record that I am not a doctor. I have X-rayed one or two fractured GSW patients, however.

[tpd223]

In the shootings that I have seen I have not noted 9mms having any great difficulty in breaking bones. The biggest issue it would have is being typically loaded with a semi-pointed RNFMJ bullet.

[DocGKR]

Dr. Lane compared 9mm 115 gr and 147 gr JHP with .45 ACP 230 gr JHP --the .45 ACP created greater bone damage and were more likely to punch through the swine femurs than the 9 mm's.

IIRC, no 9 mm shots were deflected by ribs during the 1986 FBI incident in Miami.

Lot's of handgun projectiles of all calibers, including .45 ACP, have deflected off various maxillofacial and cranial bony structures and failed to penetrate into the cranial vault during actual shooting incidents.

There is no good way to quantify bone, due to varying sizes, shapes, and densities of living bone, as well as variations in striking angles.

If you really need to shoot through bone, use at least a .44 Magnum or better yet a rifle cartridge or 12 ga Brenneke slug...

[BBMW]

I'm dredging this up from the dead thread underworld because I was thinking along the same line, did a search and found this.

I had a follow on question for Doc, and anyone else, which is:

Would the fact that bone penetration/deflection is a issue, and it's something that isn't accounted for in gelatin testing, tend to be a modifying factor in any decisions about caliber and load selection based on gelatin testing. Given any level of rough equivalence between two rounds in gel testing, wouldn't you always want the heavier choice, given that weight seems to be a large factor in bone penetration?

For instance, if the choice is between a Glock 19 or glock 23, and you''d only be giving up two rounds for the ability to carry a significantly heavier bullet, would the bone penetration issue push toward the 23, all else being equal?

[Dragon Slayer]

I'm dredging this up from the dead thread underworld because I was thinking along the same line, did a search and found this.

I had a follow on question for Doc, and anyone else, which is:

Would the fact that bone penetration/deflection is a issue, and it's something that isn't accounted for in gelatin testing, tend to be a modifying factor in any decisions about caliber and load selection based on gelatin testing. Given any level of rough equivalence between two rounds in gel testing, wouldn't you always want the heavier choice, given that weight seems to be a large factor in bone penetration?

For instance, if the choice is between a Glock 19 or glock 23, and you''d only be giving up two rounds for the ability to carry a significantly heavier bullet, would the bone penetration issue push toward the 23, all else being equal?

Or better yet a 45 ACP, that Doc GKR says is the better bone performer? But in reality if you do have more rounds in a 9mm would you shoot a few more with the intent that they do go different ways and are not affected by bones?

[DocGKR]

"Given any level of rough equivalence between two rounds in gel testing, wouldn't you always want the heavier choice, given that weight seems to be a large factor in bone penetration?"

It is a factor, but so is bullet construction, velocity, weapon reliability, and "shootability".

"For instance, if the choice is between a Glock 19 or glock 23, and you''d only be giving up two rounds for the ability to carry a significantly heavier bullet, would the bone penetration issue push toward the 23, all else being equal?"

Well that is an easy one, I'd take the G19 because it is more reliable, durable, and easier to shoot. Terminal performance is only one factor; I would rather shoot a 100% reliable weapon using plain FMJ, than an 90% one with the latest high tech ammunition.

[WS6]

Dr. Lane compared 9mm 115 gr and 147 gr JHP with .45 ACP 230 gr JHP --the .45 ACP created greater bone damage and were more likely to punch through the swine femurs than the 9 mm's.

IIRC, no 9 mm shots were deflected by ribs during the 1986 FBI incident in Miami.

Lot's of handgun projectiles of all calibers, including .45 ACP, have deflected off various maxillofacial and cranial bony structures and failed to penetrate into the cranial vault during actual shooting incidents.

There is no good way to quantify bone, due to varying sizes, shapes, and densities of living bone, as well as variations in striking angles.

If you really need to shoot through bone, use at least a .44 Magnum or better yet a rifle cartridge or 12 ga Brenneke slug...

I always figured that the more velocity and energy present, the better a projectile would do against a bone, with regard to deflection vs. penetration.

Never shot any large bones, but this seems to be the case regarding metal and wood. I know neither of these are bones, though.

[DocGKR]

Bullets that do well against bone generally fare well against automobile windshield intermediate barriers.

[WS6]

Bullets that do well against bone generally fare well against automobile windshield intermediate barriers.

Which would mean that they are all about equal using bonded rounds in 9/357/40/45, no?

I wish there was a way to get ahold of some deflection test #'s between those rounds and windshields. I know OP has done some, but I was wanting something like:

"XX load inches of deflection from point of aim 24" behind windshield at compound angles of XX* and XX*."