While this is a minor detail, 45 Degrees will never be an optimal angle. If you are shooting in a vacuum which only effects bullet speed, you still have gravity to contend with. If you eliminate the gravity in a vacumm, then 45 degrees is far to inefficient as compared to a flat trajectory where the bullet has no limits on distance. Optimum angle is generally at 30 to 32.5 degrees and that includes the 16" guns on the Iowa class battleships.
Lethal distance of hi powered rifles?
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It is imposable(unless it hits your eye, but you would have to be looking straight up) for a bullet to kill someone in true free fall. If it is fired with any angle then it can kill on the way down. But true free fall, by a bullet fired straight up in the air will not kill someone on the ground. The terminal velocity of a bullet will not kill you. The thing is it is very hard to actually fire a round straight into the air. So when people shoot at new years party's in the air, there bullets are coming down at an angle not straight down.
http://www.loadammo.com/Topics/March01.htm
also, myth buster's did it and received the same answers. again only if its fired straight up in the air.
Jim Watson
New member
Sorry, Trapper, in a vacuum with no force on the bullet except gravity, and with a range short compared to the radius of the planet, a 45 degree launch angle will indeed give the longest range in a pure parabolic trajectory.
I agree with you, mindwip, a bullet dropping straight down at terminal velocity would be painful but not lethal, according to Hatcher's work. I doubt many New Year's drunks use a plumb bob to align their shots in the air, and if there is any angle at all, the bullet will come back down with some residual velocity, enough to be dangerous.
I agree with you, mindwip, a bullet dropping straight down at terminal velocity would be painful but not lethal, according to Hatcher's work. I doubt many New Year's drunks use a plumb bob to align their shots in the air, and if there is any angle at all, the bullet will come back down with some residual velocity, enough to be dangerous.
FirstFreedom
Moderator
Sorry, that is incorrect. It most certainly could kill a person, coming straight down, depending on a variety of different factors:
Did the bullet turn around due to wind or bullet contruction such that the nose rather than the base is heading down first on the way down? If nose first, then what is the BC of the bullet? BC applies in cutting the wind straight down too. The higher the BC, the higher the terminal velocity from gravity. Also, the higher the BC and the highly-correlated SD, the higher it's penetration ability through the skull, so again, depends on whether the bullet turns around, and to what extent it turns around, and the BC. Also, if it does NOT turn around, then what's the BC of the bullet's BASE (which at that point becomes its nose)? Is it a boattail bullet, which will then have a higher BC than a flatbase?
Next, what's the weight of the bullet? The heavier the bullet, the deadlier, due to sheer momentum, which can translate into more penetration and crushing of skull bone. Further, regardless of whether it penetrates, the sheer weight concussing the skull can cause brain trauma or death, due to the massive jolt, if the bullet is big enough. Is it a 700 gr 12 ga slug? 750 gr .50 bmg? Going terminal vel? Are you kidding - death would be more likely than not.
Next, what's the bone density and resiliency of the person in question? Is it a baby getting hit in the soft spot? Is it a young person with flexible bones but not very thick and hard bones (skull)? Is it an elderly person with osteoporosis?
Next, is there any downward wind shear force aiding the bullet's velocity with a "tailwind"? Wind goes in all directions, not just left and right on a 2-dimensional scale. Many factors come into play, and I assure you that a bullet in the brain can be deadly, and there is a high probability that a given bullet will penetrate a skull.
Lookit, there is no magical sharp distiction between a bullet shot directly up at 90 degrees with a plum, versus a bullet shot at 89.999995 or 90.000005 - that's got nothing to do with it. Any bullet in the *general* range of 80 to 100 degrees, give or take, as far as the horizontal vector goes, is going to have a VERY minimal amount of a horizontal energy/momentum, from that particular vector - the damage comes from the bullet more or less stopping at its apex, turning around and coming down at its terminal velocity (if it has enough time to reach terminal, which most any bullet would). There is no magic distinction on either side of 90 degrees. At SOME point along the scale, the horizontal vector is low enough that momentum/energy is carried horizontally, at least until that point near the very end of the trajectory, where the parabolic curve is such that the drop rate is much higher than horizontal momentum, due to energy bleed from air resistance.
Theoretically at least, a bullet fired directly vertically would have the same velocity upon returning to earth as it had when fired minus some velocity loss to air resistance. The round is fired, the acceleration of gravity slows it down, it stops momentarily, then the acceleration of gravity accelerates it towards the earth again. Same as if you jump off of a trampoline, or throw a ball into the air, etc. In fact, the calculation is much easier when you talk about firing the bullet vertically, as the calculation gets less complicated.
Assume-
3,200 fps muzzle velocity
Acceleration= 32 ft/sec/sec (G)
Time= Velocity/G = 100 seconds to stop
Then conversely, upon returning to earth
Velocity= Acceleration (G) X Time= 32 ft/sec/sec X 100 sec= 3,200 fps
I will accept that there is velocity loss due to air resistance both on the ascent and descent, but even ifyou were to lose 1/2 of the initial velocity to air resistance, you can see how a bullet fired into the air is still very dangerous when returning to earth.
Assume-
3,200 fps muzzle velocity
Acceleration= 32 ft/sec/sec (G)
Time= Velocity/G = 100 seconds to stop
Then conversely, upon returning to earth
Velocity= Acceleration (G) X Time= 32 ft/sec/sec X 100 sec= 3,200 fps
I will accept that there is velocity loss due to air resistance both on the ascent and descent, but even ifyou were to lose 1/2 of the initial velocity to air resistance, you can see how a bullet fired into the air is still very dangerous when returning to earth.
Jim Watson
New member
You lose a lot more than half the muzzle velocity.
Hatcher concluded from actual vertical firing tests and followup calculations that a .30-06 bullet would reach a terminal velocity of 320 fps, with about 30 ft lbs energy for the 150 grain FMJ. At that time the Army considered 60 ft lbs necessary for a significant wound.
If there are any more recent TESTS, it would be interesting to hear of them.
Newspaper accounts need not apply unless they give the locations of both the shooter and the victim, and they are close enough to document truly vertical firing.
Hatcher concluded from actual vertical firing tests and followup calculations that a .30-06 bullet would reach a terminal velocity of 320 fps, with about 30 ft lbs energy for the 150 grain FMJ. At that time the Army considered 60 ft lbs necessary for a significant wound.
If there are any more recent TESTS, it would be interesting to hear of them.
Newspaper accounts need not apply unless they give the locations of both the shooter and the victim, and they are close enough to document truly vertical firing.
Things in free fall will only reach so much speed, terminal velocity, it is somewhere in the 200 MPH range if memorry serves me. So 200 MPH X 1.46 feet per second would be around 300 fps terminal velocity. These numbers are not exact but not far off either.
I tend to agree with a lot of FF's post in that the weight of the bullet and if it hits sideways or point first would all play into the amount of damage one might expect to receive.
Is why I wear a cap all the time when outside.
You may be corect on the speed Jim, I thought terminal velocity was around 220mph or so, but I an not sure.
My mistake I miss read 320 as mph not fps.
I tend to agree with a lot of FF's post in that the weight of the bullet and if it hits sideways or point first would all play into the amount of damage one might expect to receive.
Is why I wear a cap all the time when outside.
You may be corect on the speed Jim, I thought terminal velocity was around 220mph or so, but I an not sure.
My mistake I miss read 320 as mph not fps.
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There have been some tests with vertically fired bullets. The bullet does not turn around and come down point first. Why would it? The heavy part is at the rear. It simply stops in mid-air and falls back down, base first. It will not drop any faster than the same bullet dropped from that height. Measurements indicate that the energy at terminal velocity is not enough to cause serious injury, though in a fluke situation (such as a person looking upward being struck in the eye) there could be a severe injury.
Many people have campaigned against guns, or at least against using guns in celebrations, because bullets coming down have caused death or serious injury. But "coming down" is not the same as "coming down perfectly vertically". If a bullet is fired at, say, a 45 degree angle, the bullet will "come down" but it will still have a high proportion of its initial velocity; it is not in free fall. And of course, it can cause injury or death.
In any case, firing a gun into the air, or firing a gun in any direction in which the point of impact is unknown, is not good practice, and can be hazardous.
Jim
Many people have campaigned against guns, or at least against using guns in celebrations, because bullets coming down have caused death or serious injury. But "coming down" is not the same as "coming down perfectly vertically". If a bullet is fired at, say, a 45 degree angle, the bullet will "come down" but it will still have a high proportion of its initial velocity; it is not in free fall. And of course, it can cause injury or death.
In any case, firing a gun into the air, or firing a gun in any direction in which the point of impact is unknown, is not good practice, and can be hazardous.
Jim
Some of the top of the line bows are sending an arrow about 300fps(very fast). Arrows are, a little heaver than most bullets, however I wouldn't want one to hit me on the "Wood". The discovery episode titled "Magic Bullet" came to mind reading this post. The velocity of that bullet was very close to 300fps if i remember R
I've never been able to get a good idea of how the army decided that 60ft/lbs was the threshold for serious injury.
There have certainly been documented deaths from conventional pellet guns and even powerful conventional pellet guns tend to run in the low twenties ft/lb range.
There have certainly been documented deaths from conventional pellet guns and even powerful conventional pellet guns tend to run in the low twenties ft/lb range.
warrenhunting
Inactive
Completely worthless knowlege to a whitetail!!
Sorry Mr. Watson, Trapper is correct on the trajectory being optimum below a 45 degree angle in a vacuum. If there is still gravitational interaction with the bullet, there is no possibility of a perfect parabolic arc as there is a specific degradation of linear velocity, relative to gravitational interference, of the climb that cannot be duplicated by gravitational acceleration on the downward portion of the arc. However, this is all hypothetical physics. If a high density projectile launched in excess of 3000 fps were fired at a 45 degree angle to the planer gravitational axis of the earths surface without the confines of drag, or other atmospheric interference, there would be no "arc" as it would quite simply escape the bonds of gravity and become nothing more than a space bullet.
Sorry Mr. Watson, Trapper is correct on the trajectory being optimum below a 45 degree angle in a vacuum. If there is still gravitational interaction with the bullet, there is no possibility of a perfect parabolic arc as there is a specific degradation of linear velocity, relative to gravitational interference, of the climb that cannot be duplicated by gravitational acceleration on the downward portion of the arc. However, this is all hypothetical physics. If a high density projectile launched in excess of 3000 fps were fired at a 45 degree angle to the planer gravitational axis of the earths surface without the confines of drag, or other atmospheric interference, there would be no "arc" as it would quite simply escape the bonds of gravity and become nothing more than a space bullet.
Way to resurrect a 6 and a half year old thread. In any case, its negligent to fire a bullet beyond what you can see. There was a girl killed in a swimming pool a few years ago when some guy shot a .30-06 into the air. He was 1.6 miles away when he pulled the trigger. At least he had the shame to turn himself in.
Boomer58cal
New member
Nonsense... That's an arbitrary statement. It totally depends upon the mass and ballistic coefficient of the bullet in question. If you drop a big enough bullets out of the sky and it hits you on the head, it will kill you.
I remember about 10 years ago there was a guy in LA that complained of headaches for several days, when he went to the hospital they found a 22 lr bullet about an inch and a half in his brain. The bullet came straight down. It was a few days after New Years and the guy couldn't recall when he was struck by the bullet.
The doctor said if left untreated for a few more days he would have died.
Boomer
Jim Watson
New member
Sorry, warrenhunting, the escape velocity of Earth is approximately 7 miles per second or 36960 fps. No 3000 fps "space bullets" around here.
And I still disagree with Trapper after six years. Gravitational deceleration on the up leg of a 45 deg launch will be matched by gravitational acceleration on the down leg IN A VACUUM. It will come down at the same velocity and angle with which it left, IN A VACUUM.
And I wonder how we knew that Boomer's bullet came straight down?
The guy didn't recall where or how he got shot, so who was there with a plumb bob. I figure that it was like most far fetched "accidental" shootings, he was trying to cover up a dispute that turned violent and then everybody was sorry.
And I still disagree with Trapper after six years. Gravitational deceleration on the up leg of a 45 deg launch will be matched by gravitational acceleration on the down leg IN A VACUUM. It will come down at the same velocity and angle with which it left, IN A VACUUM.
And I wonder how we knew that Boomer's bullet came straight down?
The guy didn't recall where or how he got shot, so who was there with a plumb bob. I figure that it was like most far fetched "accidental" shootings, he was trying to cover up a dispute that turned violent and then everybody was sorry.
Boomer58cal
New member
You obviously know better than the doctors that examined him. 
The ones that said due to the velocity of the impact it must have fallen out of the sky.
A 40g 22lr bullet falling at terminal velocity has more energy than a standard 8g .177 pellet at 750 fps.
Boomer
The ones that said due to the velocity of the impact it must have fallen out of the sky. A 40g 22lr bullet falling at terminal velocity has more energy than a standard 8g .177 pellet at 750 fps.
Boomer
psychopuppy1
New member
1) The jumper from the balloon broke the sound barrier, no propulsion, just jumped ! That's faster than terminal velocity!
2) I heard, just yesterday) on the radio, of a guy who was driving down the road, and got hit in the pumpkin with a bullet! It DID NOT kill him, or even enter his skull, but it did tear up some skin, and needed to have 16 stitches!
3) Hunting in the Adirondacks one year, heard a shot, WAY off in the distance.3 or 4 seconds later, heard a buzzing, getting louder! We hit the dirt, and the bullet smacked the tree behind where I was standing! It was definitely a ricochet , but it still had some punch!!
2) I heard, just yesterday) on the radio, of a guy who was driving down the road, and got hit in the pumpkin with a bullet! It DID NOT kill him, or even enter his skull, but it did tear up some skin, and needed to have 16 stitches!
3) Hunting in the Adirondacks one year, heard a shot, WAY off in the distance.3 or 4 seconds later, heard a buzzing, getting louder! We hit the dirt, and the bullet smacked the tree behind where I was standing! It was definitely a ricochet , but it still had some punch!!
Brian Pfleuger
Moderator Emeritus
No sense in resurrecting a 7 year old argument, particularly with a patently incorrect first post.
In case anyone wonders, the escape velocity on earth (without considering air resistance) is ~36,736fps, roughly 10 times faster than a fast rifle bullet.
warrenhunting said:
In case anyone wonders, the escape velocity on earth (without considering air resistance) is ~36,736fps, roughly 10 times faster than a fast rifle bullet.
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