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You are overestimating what current physics theories can predict. Sure, you can possibly calculate kinetic energy at x feet from the muzzle but you need real world tests to know exactly what effect that will have on human skin, bones, other organs, and fatality. That requires tests that measure bullet expansion and penetration for vital organs. Many people have taken the position that a handgun round fired into the air cannot kill an innocent person as it comes down based on calculations yet it has happened many times.
Here is a picture of a bird killed by a slingshot.
I got my first bullet-proof vest when I was 15. My best friend volunteered to wear it and let me shoot him with various small rounds. I turned that offer down because you cannot predict what will happen in the real world. Plus, it would really hurt because mushrooming bullets against your body really suck even if there is no penetration.
I’ve got a cronograph but I’m not sure it can register velocities that low. I’ll ask around to see if anyone I now has a NAA mini revolver and see if I can clock some shorts and BB caps.
Grow up in a bad neighborhood?
Not at all. My father was a Federal Firearms Dealer and we had every gun you can imagine at our house including machine guns. We also had three gun ranges: rifle, pistol, and skeet. I always dreamed of a bullet-proof vest for some reason so my father bought me one for my birthday. I still have it hanging in the closet next to me although it is a little small now. I once hung it on a tree and shot it with a .22 and they didn’t penetrate so I was happy.
My best friend was and is a psycho in that way. He was dead serious when he said that he wanted me to shoot him with it on. I don’t think it is a good idea to shoot your best friend even if he is wearing protection.
Okay, here’s some physics, though I don’t know why the basic kinetic energy equation [K= 1/2 mv[sup]2[/sup]] won’t tell you every thing you need to know.
From the data in the article you linked, the measured muzzle velocity of a .22 LR round is *700 fps. This is actually a surprisingly high number. Many standard pistol firing this kind of round only have muzzle velocities in the 900 fps range, so the 1 1/8" barrel has about 60% (700[sup]2[/sup]/900[sup]2[/sup]) the kinetic energy of a more standard pistol, which most certainly can penetrate the skin.
Bullet shape would play a very significant role. I can’t be the only foolish third grader to have done impromptu penetration tests of T=square crossbows, firing pencils under rubber band power. A “brocolli band” and a sharp #2 pencil could easily have done some very respectable penetration, based on my results on various paperbacks and booklets. (From what I hear, some kids in my junior high took the test to the actual flesh level, but I never saw the results firsthand]
I can also personally attest that a “wrist rocket” type slingshot, with a much lower projectile velocity (i.e. the projectile was a visible blur, unlike the slowest bullet) could sometimes pentrate 3/4" pine at extreme draw, or easily and consistently penetrate 1/8" plywood or kill a small animal (with skin and body penetration) at normal draw. No, I was not a psychopathic child. I simply grew up near some woods in a state where hunting was a common activity.
While I’ll leave the technical debate to the avid technical shooters, I feel the difference between a .22SR and .22LR will be fairly modest in a 1 1/8" barrel. The bullet experiences the maximal initial impulse, due to the extreme confinement of the gases in the brief time the bullet is in the barrel [which is ordinarily the very beginning of tis trip down the longest barrel, but neither round will be able to impart anything near the ultimate velocity it is capable of. “Normal” pistol barrels are several times that length, and rifle barrels are at least 14.2 times as long (in most states, a rifle is defined as having a minimum barrel length of 16 inches)
A quick estimate, based on that measured figure, suggests that the bullet would spend roughly 270 microseconds in the barrel. I’d want to hear from the technical shooters about the time required for complete combustion of the powder in the cartridge, but I wouldn’t be surprised if it wasn’t on the order of 20 microseconds, and if there was barely time for the often ignored elastic phase of bullet firing to take place: the bullet would compress longitudinally, expand slightly radially, and [begin to?] seat in the barrel grooves, then almost immediately leave the barrel.
In this actual test, a 900 fps 22 LR round was shown to pentrate two standard interior walls and an exterior wall before lodging in a second exterior wall. In Boston, we have several cases a year of serious injury or fatality from 22 LR round that have penetrated a wall. If those bullets began with a muzzle velocity of 900 fps, and lost 40-50% of their kinetic energy before impacting human flesh, they would be roughly equivalent to a shot fired by the specified 1 1/8" barrel. The mass and
In numerical terms: a 2.6 gram (40 grain) .22LR round fired from a pistol at 900fps (275 m/sec) would carry about 197 joules of kinetic energy. The same round at 700fps (213 m/sec) would carry about 118 joules. By contrast, a 400 grain (26 gram) arrow at much slower bow-launched velocities (e.g. 175 fps or 53 m/s) carries only 112 Joules, but can easily penetrate animal flesh with a rounded conical (ogival or bullet-shaped) tip. With a hunting head, it can reportedly pass completely through a deer.
It is extremely probable that a .22LR or SR, fired from the indicated gun would easily and consistently break skin. Skin is tough, but not that tough. As a toddler, I skewered myself by walking through some shrubbery into a freshly cut branch. (The first of hundreds of “What a stupid way foir me to die” moments.) It turned out to ba a fairly minor wound, of course, and healed quickly. but how many of us led such sheltered lives that we don’t have many similar tales?
Sorry, I was interrupted by work while composing the above, and posted without reviewing. I meant to note that impact kinematics (e.g. arrow or bullet deformation) will play very significant roles. The incident where I skewered myself was meant to illustrate that a very low velocity impact with a relatively dull point (which I estimate in hindsight to be 1/2-3/4" as opposed to under 1/4" for a .22 round) can break skin.
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- A 22LR has (in theory) about 110 ft-lbs energy, a 22-short has about 65 ft-lbs energy, a CB cap has about 25 ft-lbs of energy, but some range up to 37 ft-lbs that I remember. --A typical BB gun has around 5 ft-lbs of energy, for a regular BB fired at 700 FPS, or about 3 ft-lbs for a BB fired at around 500 FPS. …A 300 FPS BB gun would have all of about 1.19 ft-lbs of energy. -So even a CB cap has way more power than a typical BB gun.
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- It’s iffy to estimate how much damage is possible. On one hand, kids have been killed with ordinary BB guns, when they happen to get hit in a particularly vital area. On the other hand, any big-city ER doc can tell stories of people coming in with gunshot wounds from small pocket pistols, usually .25’s and .32’s, and the bullets are so low-powered that if they hit bone (such as a rib or in the skull) they penetrate so little that the back end of the bullet is still visible if the wound is blotted with something absorbent. Among gun enthusiasts, a 22LR pistol is generally considered more deadly than .25 and .32 pistols, because the smaller 22LR bullet penetrates better.
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