New found ballistics knowledge
Posted by peanut on Sunday Jan 11, 2009 Under as a med student, blogin, medical stuffsI had blog about the lack of knowledge about weapons before. Well, seriously, I personally think that Malaysians youngsters do not talk about guns and tanks and bombs during mamak session. This is actually a good thing I guess. Sometimes when I was sitting in lecture with my Russians batchmates and overheard their conversations, besides cars, they like to talk about firearms and bombs and tanks. Weird right?
Anyhow, I remembered when the doctor (who I idolize) who I met during the selective in India said that he had his ‘new found knowledge of psychiatry’ when he gotta treat a psychiatry patient with dystonia and possible psychological trauma after an attempt of rape (despite the fact that we are living away from the city, they have 1 or 2 psychic patients per week!), today is the day that I have my new found knowledge of ballistics in forensic medicine.
I love it when the teacher knows how to put their material nicely and talks only about the interesting things and believes his students to study the basics at home (come on we are all grown ups already).
Definition of firearm - A weapon, especially a pistol or rifle, capable of firing a projectile and using an explosive charge as a propellant. In term of medicine, 4 components are considered the main factors - mechanical, thermal, chemical and sound.
On a firearm, the column (main empty tube) of the gun can be smoothed or rifled (specially threaded). The smooth column are usually use with blunt bullets and is considered the classics (mostly used in hunting, or the shotguns). The rifled or specially threaded column is kinda like the new generation’s firearm, giving the bullet (usually sharp headed) the ability to spin, another element that make it more deadly.
When the trigger is pulled, the part of the capsule containing the explosive charge will burn up and create such big combustion in such small space that the energy was transferred on the bullet which push it out through the column. Some of the left over energy will be used to mechanically reload the next bullet (automated rifle) and continue firing until you let go of the trigger, or used to reload the next bullet (submachine gun) but will not fire until you pull the trigger again.
A normal pistol could shoot a bullet with a starting velocity of 200m/s, and the proud Russian AK-47 - almost triple the speed of a normal revolver or pistol. A sniper’s range can reach 2km.
The entering wound on a body would be very small. But once a bullet passes through the skin, it has the ability to be deviated into another body structure and finally end up blindly in the body, or travel all the way out from the other side of the body (possible in another level), creating a bigger tissue defect.
The molecular theory of the big impact created by the bullet also stated that the diameter of its influence could be 6 to 7cm (depends on the distance). It means, if you are shot by an AK-47 bullet, which is actually 3cm away from your ribs (intercostal space), it is possible that your ribs could be fractured, by the molecular impact caused by the bullet on the nearby soft tissue.
Let’s look at the protective vest instead. It basically have no use against the shooting done by AK-47. Even thou the bullet didn’t pierce through the body, the impact and energy given is big enough to fracture your organs and ribs. Remember, E=mc2(square), energy does not disappear into thin air.
Plus a gun wound is always considered an infected wound. A shot on the leg which break the femur would basically means amputating the leg if one wants to survive.
No, Rambo doesn’t exist.
No, happy ending in movies with the existence of guns doesn’t exist.
No, Mission Impossible is fake.
Yea, Hollywood movies are lame. Feeding us wrong information and wrong science yet we choose to believe them blindly.
In the end, I wondered, why all these are created.
In order to subdue a demon, you need to change into a demon eh?
AK-47 (AK actually stands for the creators name - аппарат колашниково) that can be semiautomated or automated as you like, never jams, 700m/s to 900m/s, almost 2km range and shoot even in water.
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January 12th, 2009 at 8:17 am
reminds me of Counter-Strike. I luv using AK-47 when I play CS lol!
January 12th, 2009 at 1:17 pm
yea.. come to think of it, the game is really ‘realistic’ compared to the others…
January 20th, 2009 at 3:42 am
Reasonable article, but overly simplified.
Your definition of firearm - A weapon, especially a pistol or rifle, capable of firing a projectile and using an explosive charge as a propellant.
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Accurate definition of a firearm - A barrelled device capable of firing a projectile using any of a number of propellants.
Namely:
(a) explosive charge
(b) compressed gas (typically plain air or CO2)
(c) Electromagnetic pulse or similar
The barrel may be rifled (i.e. rifles and most pistols) or smoothbore (namely shotguns, and less frequently, shot-pistols).
Rifling imparts a spin to the round which improves it’s stability in flight making it more accurate. The spin does not inherently make the bullet more deadly than a non-spinning round in the event of a hit, although it does improve the odds of you hitting your target.
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You will note that I have omitted the use of the term “weapon” from this description. Not all firearms are weapons in the same way not all knives are weapons. In fact, no object is a weapon until someone picks it up and uses it as such. “Weapon” is an abstract term. Firearms are tools, designed for various tasks -
paper punching (target shooting)/hunting/combat.
Target firearms as used by Olympic shooters and target shooters will not have had “effective as a weapon” included in their design brief. Their design specification will have been to make the firearm as accurate as physically possible regardless of weight, rate-of-fire and “stopping power”, which are all irrelevant in target firearms.
Having googled “firearm definition”, I guess you got your definition from answers.com. Sadly their definition, whilst accurate in some cases is inappropriately short and incomplete.
As for whether a ballistic vest would be effective against a 7.62mm round as used in the AK-47. That depends largely on the distance from which the round has been fired (point blank/100m/200m/stray round from 1km away) and the design of the vest - a heavy-duty vest with solid kevlar plates (which will probably stop a round, or at least render it non-lethal), or a lightweight shrapnel vest composed solely of woven kevlar fibres (in which case penetration will most likely occur).
Modern medicine means a bullet to the leg will most likely not require amputation.
Between modern anti-biotics and bone-setting techniques the bullet can normally be removed and the bone reset (unless it severs a major artery, in which case you’ll be dead in under 20 seconds anyway).
It also depends heavily on the design of bullet head. An armour-piercing round will go straight through a person and out the other side, leaving a clean hole (albeit with a slightly larger exit wound than entry wound).
On the other hand, a round from an M-16 rifle which is designed to tumble in flight will enter the body and literally rattle around the rib-cage, pureeing organs and cracking ribs.
However, one only has to see the scars borne by members of the Crips and Bloods of LA to understand that gun-shot wounds are relatively survivable provided they’re not headshots or heartshots, and medical care is provided quickly.
January 20th, 2009 at 10:44 am
Rich,
Thanks for you comments. Yea.. the article that I produced is kind of a simplified version because it is really a lot to write if I would want to detail stuffs but instead of that, I just wrote what came up in my mind that time.
There seems to be something different about what I learned and what you said. I still think that a firearm is those using explosive charge with propellant. If according to you, an air gun would be a firearm as well?
When I wrote about fracture bones, the image I had in mind is a small entry wound which shatter a bone to pieces causing secondary soft tissue injury on the inside of the body part. If the patient is admitted with a shattered femur, small pieces which is not attached to the main bones will be took out, no doubt a large defect of bones will be seen and I think modern medicine do not have a way in growing bones in an infected area yet, so I thought prosthesis and amputation is the available method? Of course, every situation and scenario is strictly individual, I’m not arguing :P
March 22nd, 2009 at 2:24 pm
Hi there,
Everything dynamic and very positively! :)
Thanks
Jinny
December 9th, 2009 at 10:54 pm
This was a great read though! Thanks..