How fast does a bullet travel?
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The bullet spins because the barrel it comes out from has bored threads. The spinning action helps the bullet maintain an almost straight trajectory.Originally posted by SibeiSuayKia:i heard from my NCC sir that a bullet actually spins..
and during the bullet's trajetory..the bullet actually spins down-ward a little
den moves upward a little..is it true?
why does a bullet spin ? i thought the charge only propells it to go infront?
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its smt about the spin stablising the bullet..go ask some physics guy..i'm not too sure about the explanation..
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Well,the round when fired spins as twists/grooves are specially cut into the barrel of the weapon,this is known as Rifling.the typical M-16S1 has approx. 7 twists in its barrel.The need for this is to give the round a straight and more or less flat trajectory and accuracy.A smooth-bore weapon(one w/o rifling) will have a shorter range and is also less accurate.
Hope this answers your question.
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http://www.newscientist.com/lastword/article.jsp?id=lw94Originally posted by SibeiSuayKia:i heard from my NCC sir that a bullet actually spins..
and during the bullet's trajetory..the bullet actually spins down-ward a little
den moves upward a little..is it true?
why does a bullet spin ? i thought the charge only propells it to go infront? -
seen one lame movie long time ago...
enemy: "haa! you have run out of bullets!!"
hero: "I have run of bullets, but I still have a lot of guns."
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Why does a bullet spin.Originally posted by SibeiSuayKia:i heard from my NCC sir that a bullet actually spins..
and during the bullet's trajetory..the bullet actually spins down-ward a little
den moves upward a little..is it true?
why does a bullet spin ? i thought the charge only propells it to go infront?
Hmm.
The next time you handle a M16, please look down the barrel.
Notice the barrel.
It's rifled.
Those cause the projectile to spin. -
for example, taurus got 'grooves' dat cause the bullet to rotate prior to leaving the barrel, dat cause the bullet to spin, causing more pene power. bullet's trajectory is similar to projectile motion loh.
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The spin is not to flatten the trajectory, not to enhance penetration, and certainly was not meant to inflict the kind of damage to tissue that are synonymous with M-16 wounds we are all told since the day we asked our intructors.
The rifling imparts a spin to stabilize the trajectory by maintaining the rotation axis of the round to prevent tumbling, something that affects trajectory stability and ultimately accuracy. To say that the round goes low then high is one of the many urban legends that I have never come across before.
The penetration is a direct result of the forward velocity and the mass of the round forming a mass momentum so powerful that if the round was as soft as liquid it will still cause considerable damage or death.
The infamous small entry wound and baseball sized exit wound is not a result of the spin. Instructors have told practically the whole world that the round spins all over the wound before it exits; if you were to take a cross section of the wound you wound realise that to be able to perform that task, the round would have to be a magic bullet to be at all the designated damage zones at the same time, which is logically impossible. What actually happens is the round will tumble inside the body, transfering its kinetic energy to the tissue around it in a process better known as "stopping power", this energy gets tranfered from the tissue around the projectile to the adjacent tissue and so on and so forth, spreading to a large area. Then the tumbled round exits. Pretty neat huh?
The rifling of an M16A2 is about 12 to 1, 12 inches 1 spin. The most you can estimate the round to spin across human body would only be around maybe 4 or 5? WHat damage can 4 or 5 spins do? -
(i) Not urban legend, just misunderstanding of how the sighting is arranged. The default is where you aim is where the round will land at 25m and 220m. At ranges closer than 25m it starts lower (that's why the canadain bull is higher at 25m and closer at 100m for zeoring), this is to compensate for the ballistic path of the bullet.Originally posted by crosshairs:..To say that the round goes low then high
The infamous small entry wound and baseball sized exit wound
The rifling of an M16A2 is about 12 to 1, 12 inches 1 spin. The most you can estimate the round to spin across human body would only be around maybe 4 or
5? WHat damage can 4 or 5 spins do?
see Figure 2-43 at http://198.65.138.161/military/library/policy/army/fm/3-22-9/c02.htm#2_1
(ii) see http://www.snipersparadise.com/wound/wrong.htm
(iii) its properly described as 1 twist every 12 inches. the bullet travels at 990m/sec hence your 4 or 5 turns rotates the bullet per second. see previous point. -
anyway our m-16s1 has the old rifling for the old m193 ball round, if i am right we have both the m855 and the old m193 ball rounds in use. The m855 is of course a better round with more penetration power and greater stability
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m-16a2 is 1 spin in 7 inchesOriginally posted by crosshairs:The spin is not to flatten the trajectory, not to enhance penetration, and certainly was not meant to inflict the kind of damage to tissue that are synonymous with M-16 wounds we are all told since the day we asked our intructors.
The rifling imparts a spin to stabilize the trajectory by maintaining the rotation axis of the round to prevent tumbling, something that affects trajectory stability and ultimately accuracy. To say that the round goes low then high is one of the many urban legends that I have never come across before.
The penetration is a direct result of the forward velocity and the mass of the round forming a mass momentum so powerful that if the round was as soft as liquid it will still cause considerable damage or death.
The infamous small entry wound and baseball sized exit wound is not a result of the spin. Instructors have told practically the whole world that the round spins all over the wound before it exits; if you were to take a cross section of the wound you wound realise that to be able to perform that task, the round would have to be a magic bullet to be at all the designated damage zones at the same time, which is logically impossible. What actually happens is the round will tumble inside the body, transfering its kinetic energy to the tissue around it in a process better known as "stopping power", this energy gets tranfered from the tissue around the projectile to the adjacent tissue and so on and so forth, spreading to a large area. Then the tumbled round exits. Pretty neat huh?
The rifling of an M16A2 is about 12 to 1, 12 inches 1 spin. The most you can estimate the round to spin across human body would only be around maybe 4 or 5? WHat damage can 4 or 5 spins do? -
yup, the rotating also serves to stabilise but according to physics, when u spin something, it will move in a direction perpendicular to the axis of rotation, dis serves to stabilise the bullet during traj and also to add abit more pene. as u have seen those gymnastics spinning the ribbon wand, as she spins it, the thing forms a spiral automatically, moving out. the same thing applies to helicopter's rotors to lift the heli itself although the blades are not such a good thing to compare against but the principal is similar. another example is spinning a rigid band ard ur finger, it will move slowly upwards although ur finger is vertical, if u increase the speed, in dis we can see dat the motion is circular as the band is rigid.Originally posted by crosshairs:The spin is not to flatten the trajectory, not to enhance penetration, and certainly was not meant to inflict the kind of damage to tissue that are synonymous with M-16 wounds we are all told since the day we asked our intructors.
The rifling imparts a spin to stabilize the trajectory by maintaining the rotation axis of the round to prevent tumbling, something that affects trajectory stability and ultimately accuracy. To say that the round goes low then high is one of the many urban legends that I have never come across before.
The penetration is a direct result of the forward velocity and the mass of the round forming a mass momentum so powerful that if the round was as soft as liquid it will still cause considerable damage or death.
The infamous small entry wound and baseball sized exit wound is not a result of the spin. Instructors have told practically the whole world that the round spins all over the wound before it exits; if you were to take a cross section of the wound you wound realise that to be able to perform that task, the round would have to be a magic bullet to be at all the designated damage zones at the same time, which is logically impossible. What actually happens is the round will tumble inside the body, transfering its kinetic energy to the tissue around it in a process better known as "stopping power", this energy gets tranfered from the tissue around the projectile to the adjacent tissue and so on and so forth, spreading to a large area. Then the tumbled round exits. Pretty neat huh?
The rifling of an M16A2 is about 12 to 1, 12 inches 1 spin. The most you can estimate the round to spin across human body would only be around maybe 4 or 5? WHat damage can 4 or 5 spins do?
the extra pene power is also caused by the perk in vel caused by spinning itself.