Does Bullet Burn with Friction in Air?

The velocity of a typical bullet does not create a large enough friction against the air to cause the bullet to heat up enough to melt.

Good job too, as otherwise it might stop before it met its intended target.

Thanks your reply is completly satisfied my curiosity

bullet speeds and trajectories is a precise science that is usually researched the military armory, though text books are available to the public, they are normally used by serious long range target shooters that make there own hand loads.

Yes with Blanks only to produse Sound.

Military salutes are performed using blank ammunition.

Unjacketed (cast lead) bullets are eroded by the friction of the barrel against the bullet and by the heat of the burning propellant while inside the barrel. The higher the velocity, the more erosion occurs. Gas checks Gas check - Wikipedia, the free encyclopedia are sometimes used on unjacketed bullets to eliminate erosion due to powder burn at the rear of the bullet. After they leave the barrel, no further erosion takes.

Jacketed bullets do not erode, normally. Most bullets fired into the air from rifles are jacketed, because unjacketed bullets would quickly foul the barrel of the weapon, due to the higher velocity produced by rifles, normally.

More than you wanted to know, I'm sure.

FIRING ANY FIREARM INTO THE AIR IS A DANGEROUS, STUPID THING DO DO.

Happiness is a warm gun...

Even starter guns are considered firearms and they are fired into the air (it's the whole point, isn't it?).

There is absolutely no reason why a starter's pistol is, or should be, pointed into the air when it is fired. It may look cool, but the participants can certainly hear the gun fire, since they are right beside the starter anyway.

I think they always do that because it looks better to fire a gun into the air. If someone had the perception that the gun were somehow aimed at them when fired it would be a bad thing.

starter pistols are shot towards the sky because the noise is louder.

i think that starter guns are fired into the air because gun safety was at one time taught at a very young age by people who understood and respected firearms and firearm safety.. people that were reckless at handling firearms were looked down on. so even a pistol that could only shoot blanks was fired in the air as a matter of civic duty and personal pride.

Any blank can kill someone if fired close enough to then....there is a paper wad that could be fatal within a few feet of the barrel. And people have been injured or killed with blanks. Firing in the air guarantees noone can be injured.

A few cases turn up in this search...

http://www.google.com/#hl=en&sugexp=ppwl&cp=17&gs_id=1v&xhr=t&q=killed+by+a+blank&pf=p&sclient=psy-ab&source=hp&pbx=1&oq=killed+by+a+blank&aq=0&aqi=g1g-m1&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=664c62411796fbc8&biw=1280&bih=840

Yes to away from person. In the Wild away from habitat.

No projectile but round cake dummy.

A starter's gun fires blanks.

Bullet rotates with its motion so if someone is hit its only small hole from outside but complete mess inside.

a bullet rotates to stabilize it during it's flight path.

It is called Rifling.

Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis. This spin serves to gyroscopically stabilize the projectile, improving its aerodynamic stability and accuracy.

It isin all small weapons except Shot-Guns [Game arms]

generally a smoothbore firearm,

Are you not confusing with tracer bullets?

The pyrotechnic base (phosphorus tail) make it visible to the naked eye.

It really does occur.

Some time ago the bullet came down through a roof and killed a baby in a crib.

After some number crunching the forensic guys located the spot and the culprit.

Hard to believe this. experiments done have proven that a bullet returning to earth does not have enough energy to penetrate a human body let alone passing thru a roof and then hitting a human and killing him/her.

While working on a resdential garage a few years ago I found a .38 slug imbedded in the asphalt shingles. apparently it was from a shot into the air, the slug never reached the wood decking under the shingles.

oilcan13

It all depends on the trajectory.

Trajectory has nothing to do with it. If it is 90, 45,30 or what ever. the bullet cannot exceed terminal velocity coming down.

oilcan13

"the bullet cannot exceed terminal velocity coming down"

I am totally onboard with that...yep...100%.

Although if a bullet is fired at a 30 degree angle, it may still be under power from the original shot by the time it reaches its target.

If you don't agree with that and are in the same crowd that believes whatever entertaining stuff "Mythbusters" puts out (very limited in their tests and not much real method there, though very entertaining at times) and think that the bullet will not penetrate a flesh and blood target at terminal velocity...then let someone fire a 7.62 at you from a 30 degree angle (whatever range would be necessary) and tell me how that works out.

The bullet doesnt need to exceed terminal velocity if its fired at a 30 or 40 degree angle, its very unlikely to have used up all of its potential energy befor it hits something at that angle, the reason firing from 90 degrees is condidered to be "safe" is because the bullet has used all of its energy befor it begins to fall back to earth, so trajectory has alot to do with it, i agree with cuban_pete, go do some tests, and come back and let us know how you feel =)

A bullet fired at 30degees will in all realistic scenarios will never decelerate to terminal velocity as unless it is fired from a height...it will hit something or the ground first.

Above 30degrees will depend on wind, muzzle velocity and projectile weight, but it is still gonna hurt, a .50 cal even at terminal velocity is still going to be a bone breaker, simply due to mass.

Regards,

Sapper

the longest possible trajectory of a bullet is at a 45 degree angle. the bullet will continue to be driven by the propellent thoughout it's entire flight path at this angle.

Every year hundreds of people are killed or injured from celebratory gunfire...what goes up, will come down....

this from wiki...

"A study by the U.S. Centers for Disease Control and Prevention (CDC) found that 80% of celebratory gunfire-related injuries are to the head, feet, and shoulders.^[6] In the U.S. Commonwealth of Puerto Rico, about two people die and about 25 more are injured each year from celebratory gunfire on New Year's Eve, the CDC says.^[3]Between the years 1985 and 1992, doctors at the King/Drew Medical Center in Los Angeles, California, treated some 118 people for random falling-bullet injuries. Thirty-eight of them died.^[7] Kuwaitis celebrating in 1991 at the end of the Gulf War by firing weapons into the air caused 20 deaths from falling bullets.^[7]"

http://en.wikipedia.org/wiki/Celebratory_gunfire

In the US, '21 gun salutes' use blanks, as do starters at sporting events...

First off, the bullet travels upward, not due to gravity, but by the force of the gun powder exploding. The G force comes in when the bullet reaches it's highest point and starts downward. The bullet will gain speed due to gravitational force (32ft/sec²), but will never arrive at ground level at the initial velocity. There was a TV program called "Myth Busters" that did an experiment, dropping small objects, like coins from a tall building. The objects did no damage. They were subject to not only G-force, but also turbulence and wind resistance. Too bad it's not true. All those crazies in the middle east shooting their AK47's in the air could help kill off some of them accidentally.

Did they drop any bullets spinning at about 200,000 RPM? Bullets leave the barrel of a rifle at that speed. They don't stop spinning until they hit something. They also don't tumble going up, they won't tumble coming down, either.

Having said that, the comment by trgrcntrl, is probably valid, too.

DON"T FIRE INTO THE AIR, NO MATTER HOW HAPPY YOU ARE!

bullet rotation only stabilizes the bullet during it's flight path. much like the spin of a football.

What is your point??? Nothing you have said here, so far, seems particularly intelligent.

Bullet will be on its flight path until it hits something, ergo it's spinning until it hits something.

a bullet starts to drop immediately upon leaving the barrel. most people would agree with you though, but it's accually the cross hairs or sights that are out of alighment with the the axis of barrel to compensate for the bullet drop at the yardage that they exspect to shoot.

I don't know where you got your "expertise" but you are totally misinformed.

A bullet will begin to decelerate when it leaves the barrel, but if it is truly pointed "up" it won't begin to drop until it gets to the top of its trajectory, which, in this case is vertical.

Only true if the bullet's vertical path is exactly aligned with the force of gravity at the point of launch. I believe the comment used the term "up" to mean at some angle above horizontal. The vertical velocity of the bullet will be V=32.2 fps x time of bullet flight x sine of angle of inclination of gun barrel to the horizontal plane.

I don't know how you can possible come to the defense of AP#1 who has proven they are ignorant of the facts regarding ballistics, and physics as well as being devoid of all common sense.

But, it's a free world.

egotists are always mired in there own expirations. jlstitt

I love a ballistics thread.

i got my expertise at the springfield armory. i'm guessing that you got yours from a civil engineering manuel.

I understood what they were saying perfectly well. Why is it rubbish to assert that a bullet starts relenting to gravity as soon as it leaves the barrel? Over any appreciable distance it is totally correct.

A bullet isn't some magical object that travels in a perfectly straight line from firearm to target.

Though somewhat lacking in "technical" aspects, the description of targeting and sighting is correct.

A bullet fired vertically follows an arc, not a straight line trajectory. I doubt many wild-eyed revelers stop to make sure that their firearm is pointed in a 90-degree angle relative to their position on the earth's surface. Besides, rotation of the earth itself would place the round slightly off of the firing position, again resulting in an arc trajectory (relatively speaking).

Poor child. We, on earth, would see an arc. But not for the reason you imply. The bullet, traveling at the same speed as the earth's surface would, indeed come back down the same "trajectory".

Friction of the air against the bullet would (be the only force to) alter the arc.

And, discounting the friction, the bullet would go back down the barrel, unfortunately, spinning now in the wrong direction to mesh with the lands and grooves in the barrel.

And the bullet may relent to the forces of gravity, but it doesn't start down (AS IN DROP) until it starts down, which it can't do until it stops going "UP".

Sve your sympathy for someone else.

It's called "bullet drop" to those in the know. You can simply google it if you want. AP#1 had a valid point on that one post. Gravity affects even the highest velocity round upon leaving the barrel. The parabolic shape of the trajectory is what is referred to and is taken into account when "sighting in" a firearm.

Wikipedia actually does this great justice:

Due to the near parabolic shape of the projectile path, the line of sight or horizontal sighting plane will cross the projectiles trajectory at two points called the near zero and far zero in case the projectile starts its trajectory (slightly) inclined upward in relation to the sighting device horizontal plane, causing part of the bullet path to appear to rise above the horizontal sighting plane. The distance at which the firearm is zeroed, and the vertical distance between the sighting device axis and barrel bore axis, determine the apparent severity of the "rise" in both the X and Y axes (how far above the horizontal sighting plane the rise goes, and over what distance it lasts).

Many firearms ballistics tables and graphs show a rise in trajectory at distances shorter than the one (far zero) used for sight-in. This apparent "rise" of the projectile in the first part of its trajectory is relative only to the sighting plane, and is not actually a rise. The laws of physics dictate that the projectile will begin to be pulled down by gravity as soon as it leaves the support of the barrel bore at the muzzle, and can never rise above the axis of the bore.

That's all I was saying.

In a frictionless and zero gravity senario, the bullet would retain it's spin and would never come back. In a frictionless only case, the bullet would stop and reverse direction, but in the same position (pointy end up). There would not be any rotation because rotation is caused by the rifling.

GA

But I have to say that at least 80% of the posts here are complete rubbish.......not just the APs.... I have NEVER seen a CR4 blog with so much crap in it!!

If we say that 80% (at least) are from posters of US citizenship, the country where many people are privately armed, then the level of knowledge here demonstrates just why there are so many shootings and deaths!!!

QED

I have to agree with you. Sometimes I feel really embarrassed by my fellow countrymen's lack of common sense.

Sorry! Not defined properly!

It is true that Gravity of Earth starts pulling down as soon as the bullet leaves the Muzzle, but starts to drop only after it has reached its max height [due to the trajectory given by the 'Sight' of the arm by the firer].

Trajectory

Arms Sight types

<< Trajectory is a description of the path of a mass accelerated to a velocity and the interactions of various forces on the mass in "flight". >>

It is the ANGLE to which the Muzzle of the Barrel is lifted from the Normal.

It caters for the Gravity Pull for a particular arm, its type of amminition; Charge of the shell; Weight of the projectile; the distance to the Target.

"Sight of one type of arm differs from the other type and calculated on its own data.

Line of Sight is and the Sight of an Arm are 2 different things.

The firer is looking the target through the sight is Line of Sight; but The Sight of the Arm is setting the angle at which bullet is fired to counter the Gravity and other effects; to hit the target.

Haajee,

The Definition on Trajectory is as follows: -

trajectory

1. (Engineering / Aeronautics) the path described by an object moving in air or space under the influence of such forces as thrust, wind resistance, and gravity, esp the curved path of a projectile

2. (Mathematics) Geometry a curve that cuts a family of curves or surfaces at a constant angle The Trajectory of the mass or bullet will cross the line of sight twice, once on the way to the top of the curve and once on the way down. These are the zero point where line of sight and the trajectory are the same. A .223 (5.56mm) 55grain round will have zero points at approx 100m and 175m with my prefered loading. Since I know th trajectory, I can place the point of impact at any point within the effective range of the round. Regards,
Sapper

At a stretch, the OP is about - firing upwards, traditionally at about 45 degrees.

How we got to an argument on 'drop' in a horizontal ballistics table context is a bit beyond me.

And whoever is marking posts OT because they think gravity is not immediately acting in some manner on muzzle exit - (be that substantially as 'drop' in the horizontal context, or substantially as retardation in the vertical context) - is severely comprehension challenged or plain ignorant.

Good answer, I think we went way beyond the original question. Yes, there was a question relating to trajectory and velocity, but the simple answer is that they use blanks to fire salutes.

OK

Myth busters also did an experiment of shooting different caliber guns into the air and recovering the spent bullets. the conclusion that they came to was that although a falling bullet could hurt when it hit You it did not have enough velocity to penatrate your body or to kill You.

oilcan13

Not exactly. The terminal velocity is determined more by air resistance in relation to mass than by the mass alone. As a bullet is streamlined, its terminal velocity is going to be high enough to remain deadly. As for the horizontal velocity, that is subject to the same force due to air resistance as the vertical component, and the same considerations apply.

GA

I still would not want it bouncing off my head.

I watched as a person was knocked out by a 1/2" bolt that fell about 12 to 15 feet from a overhead crane. A large caliber bullet falling at its terminal velocity could certainly cause injury or death.

The practice should should change to shooting straight down (not at an angle!) that way the only thing you could kill is your own foot(feet, or small vermin )

I agree with trgrcntrl. There's this terminal velocity which limits the maximum speed where an object can fall. The T.V. occurs when downward acceleration (which keeps reducing due to the friction or drag caused by the atmosphere) equals to the gravity, until its acceleration equal to zero, meaning no change in velocity.

Bullets are like women, some are smaller and some are larger. Some are feather weight, others are pretty hefty. Dusting off my Speer Reloading Manual for Rifles and Pistols, bullets can leave a barrel in various velocities from 500 f.p.s. to 6000 f.p.s. The weights can span 40 gr. to 260 gr. Either way, being hit by falling objects, especially bullets, brings to mind that helmet time is my favorite time. Though all bullet testing i've done has been somewhat horizontal in nature, rarely vertical. Bullets do not burn with friction of the air, though no one mentioned the "yaw" a bullet takes while on its way to its intended destination.

We're not ready for yaw, yet.

i have seen high velocity bullets disintergrate after leaving the gun barrel. it is not due to heat, but instead involves the rotational speed [rpms] of the bullet and the thickness of the copper jacket. most bullets are composed of a soft lead core surrounded by a copper jacket. if the copper jacket fails, the lead core can disintergrate into dust from centrifical force.

Im sure it is possible in some freak instance that a falling bullet may harm or possibly kill, however as others have stated, once the bullet stops accelerating, and begins to fall back to earth, the maximum speed it can achieve is related to its mass, as a bullet is rather small, its terminal velocity, (the speed at which a falling object stops accelerating) would not be equal to the velocity of its upwards travel, same basic principal, its the reason no one is ever killed by rain drops =) *please excuse any bad spelling lol

Here, i did some fast math, its not my strongest suit, so forgive me if there are some errors, but essentually, At terminal velocity, a .44 caliber bullet will impact 128 times more energetically than a .22. A .22" diameter lead sphere has a terminal velocity of about 30 feet/sec (20.5 mph); it might raise a small bump on your unprotected bald head. A .44" diameter lead sphere has a terminal velocity of about 120 feet/sec (82 mph); it might kill you. Bullets are longer than their diameter, so they fall faster than spheres of the same diameter. A bit of a random burst here lol, but possibly usefull lol

did you factor in the bullet co-efficentcy?

I would think that the majority of people hurt from bullets fired in the air, are shots made from less then 90 degs. So the bullet retains some of initial velocity when it impacts the person. A bullet fired strait up till it stops and returns to earth with only its terminal velocity has much less chance of hurting someone.

GA and funny too!! Perfect!!

People are regularly hurt or killed by falling bullets. I lived in Beirut during the war where firing in the air was a normal part of celebrations. At new year there were often reports of people being hit. In our building we had lumps of cement knocked out and a steel door dented by falling bullets. There was obviously enough energy left to kill or seriously injure.

What goes up must come down.

BEIRUT ... A lot of irresponsible people fire in the air without looking where exactly they are pointing their guns! They just lift their arms up and pull the trigger, which makes the aim just anywhere from 45 to 90 degrees ... the sound of their fire arms scares them it seems... If you are living in a flat somwhere between the 5th floor and upward, you are very likely to be hit by a direct shot!! Hence the bullets in the metal doors (??).

This was a semi basement flat and there was no doubt from both the position of the flat and the shape of the chips and dents that the bullets were falling. A direct shot would have probably penetrated the steel. Friends had a hole in the (steel) roof of their VW van from a falling bullet. The shape of the hole suggested it was falling almost vertically.

Yes, Yes I do agree with you.

The door issue will be more likely a non vertically aimed shooting since the angle of the fall must be quite near horizontal to reach such a low positioned door. Maybe from far away to the location but still a very near horizontal firing which came down after a long travel.

The roof issue: I also had experience of bullets coming down a warehouse metal roofing making a neat hole in the sheet.

Mr. Sanjayvt;

Yes, a bullet aimed upward will continue in the direction fired, and will be acted upon by friction based on its flight stability and environmental factors that serve to slow it down, as well as by gravity acting to draw it towards earth.

Unless it strikes a target, it will arrive at ground level with a terminal velocity much slower than muzzle velocity, since it is not being fired in a vacuum.

If it hits someone they will be damaged based on many factors, including mass and velocity of the bullet as well as location of the impact on the body. Most of such incidents result in injury to the head or upper body, since the bullet is typically 'falling' from above, and yes, many unfortunately result in death. We do not hear about very many of these, because they rarely happen to someone 'famous' and the places they occur most are not covered by western journalism that dominates most media.

The only conservation of momentum issue is represented by the mass and velocity of the bullet, which will be transferred to the victim as their body gradually reduces the bullet to a stationary location within, or slows it down as it passes through, that portion of their body.

Small shotgun BB's, for instance, have very little momentum to transfer when falling from an elevated height and may be only an annoyance unless one is looking up with open eyes at the time.

Your 21-gun salute is not applicable as these are performed (in the civilized world) using blanks.

Rowdy 3rd world ignoramuses, however, do often kill unsuspecting neighbors by firing automatic rifles or even larger weapons upward over inhabited areas. And then there is the DAILY barrage of rockets, mortars, bullets, and other miscellaneous matter into the air over the residential neighborhoods of Israel, any time a neighboring moron gets it into his empty head to celebrate his desert deity by randomly firing into the air over innocent backyards. Look up injuries due to falling armament over school children in any city around Jerusalem and you will find a shocking number of examples of your query.

I thank you and all otheres as well for your response I now have the clerity I was seeking.

your welcome. in accuallity we are just debating your question amongst ourselves in a vain atempt to justify our own self-worth.

1. It is the combined forces of gravity and air resistance that slows a bullet fired vertically.

2. Bullets don't travel fast enough to burn.

3. A vertically fired bullet will not regain it's original muzzle velocity when falling due to air resistance. A falling bullet, like any other object has a terminal velocity.

4. It may fall fast enough to injure or kill.

The ignorance displayed here is astounding.

One of you would have me believe that an object that is going up is really going down and the other would have me believe that a bullet stops spinning when it reaches the high point of it's flight.

I give up!

So true, so true.

I gave you a GA to null out the OT that you got....

I think that no-body knows the actual position of Gun Salutes.

I have seen in my life more often in boyhood as it was performed in our neighbourhood away from public.

No live ammunition is used but Blanks are fired - Blanks mean Charge in case is filled - not full but much less and no projectile [the thing which actually goes to the target.]

is fixed but some dummy to produce sound is fitted. Aimed towards wild. It hardly goes some 100 yards as it is not round like a projectile but a round cake filled probably with sand or mud.

The blanks often have a white metal plug in them that is turned to gas when the gun fires and this gaseous metal cleans the gun's bore out. This means that the gun remains only "one shot dirty", no matter how many are fired.

This is done in blanks and live shots with most cordite cartridges. This makes the maintainers job far easier.....

40mm Bofor Guns used a different system as they needed to have a "Bullet/shell" shape for the loader mechanism to load correctly and the weight of the shell to recoil and reload the gun correctly. So a thick plastic bullet is used and its filled with lead shot to the same weight as the normal HE shells weigh.

When firing, the plastic bullet and the lead shot are totally vaporized. There are thick black clouds (probably not good for you) shot out of the gun, but no solid object comes out of the barrel....OH! and a loud bang!!!

Incidently, of all the big guns I worked on, dropping the shell or other damage it is next to impossible to cause an unwanted explosion due to many "safety checks" inside the shell.

9G+ acceleration, 1800RPM spin are all detected before the shell becomes live!!!

Bofors ammo is/was(?) very dangerous as the act of ramming into the breech, breaks a lead wire and makes the fuse active, a light tap could cause an explosion. If we accidentally dropped a clip (5 x 40mm fixed), we carefully picked it up and threw it over the side of the ship......never did we try and load it for firing....

Not sure why you got an OT for that - seemed directly related to the first line of the OP and quite informative - so I've 'canceled'.

It's a pity Mythbuglers didn't fire 40mm (un-fused) straight up and stand under it.

Or 12g solids. Or 20mm. Or 30mm. Or 155

Fun thread though

the white plugs you mentioned is probable wax. modern slow burning gun powder won't explode unless it's under pressure.