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Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 1:56 pm
by warnmar10
Charles L. Cotton wrote: 
Free-falling rounds simply do not have the energy to penetrate the skull or significantly deep into soft tissue. As The Wall noted, Myth Busters did a segment on this sometime back.
This is terribly sad and so preventable. I hope the person who did this is caught and prosecuted.
Chas.
Bullets fired into the air maintain their lethal capability when they eventually fall back down.
busted / plausible / confirmed
In the case of a bullet fired at a precisely vertical angle (something extremely difficult for a human being to duplicate), the bullet would tumble, lose its spin, and fall at a much slower speed due to terminal velocity and is therefore rendered less than lethal on impact.
However, if a bullet is fired upward at a non-vertical angle (a far more probable possibility), it will maintain its spin and will reach a high enough speed to be lethal on impact. Because of this potentiality, firing a gun into the air is illegal in most states, and even in the states that it is legal, it is not recommended by the police. Also the MythBusters were able to identify two people who had been injured by falling bullets, one of them fatally injured. To date, this is the only myth to receive all three ratings at the same time.
http://mythbustersresults.com/episode50
Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 2:36 pm
by sugar land dave
This is why I was home under my roof during NYE. In Sugar Land you could hear many gunshots for several hours. What goes up does come down in most cases.
Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 2:51 pm
by Scott B.
Looked to see if there had been any prosecutions for this, all I could find in the Chronicle was a March 12, 2015, article:
"At the time of the incident, police said, no one at the home had been shooting firearms. Police also said investigators suspected at the time that Rivera was killed by a stray bullet fired into the air in celebration of the New Year. No one at the home had been shooting firearms.
The Harris County Institute of Forensic Sciences now has ruled the death was a homicide."
Unless the police pick up the gun somewhere down the road, or somebody talks, I imagine it's pretty hard to identify a suspect.
Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 3:04 pm
by ScottDLS
warnmar10 wrote:Charles L. Cotton wrote: 
Free-falling rounds simply do not have the energy to penetrate the skull or significantly deep into soft tissue. As The Wall noted, Myth Busters did a segment on this sometime back.
This is terribly sad and so preventable. I hope the person who did this is caught and prosecuted.
Chas.
Bullets fired into the air maintain their lethal capability when they eventually fall back down.
busted / plausible / confirmed
In the case of a bullet fired at a precisely vertical angle (something extremely difficult for a human being to duplicate), the bullet would tumble, lose its spin, and fall at a much slower speed due to terminal velocity and is therefore rendered less than lethal on impact.
However, if a bullet is fired upward at a non-vertical angle (a far more probable possibility), it will maintain its spin and will reach a high enough speed to be lethal on impact. Because of this potentiality, firing a gun into the air is illegal in most states, and even in the states that it is legal, it is not recommended by the police. Also the MythBusters were able to identify two people who had been injured by falling bullets, one of them fatally injured. To date, this is the only myth to receive all three ratings at the same time.
http://mythbustersresults.com/episode50
If a bullet is fired upward at close to vertical (close to 90 degrees) it will always have much more vertical velocity than horizontal, but gravity will eventually burn off "ALL" its vertical velocity, then it will fall back at around max of 120 fps (terminal velocity in 1 atmosphere). It won't have much horizontal velocity at all (depending on angle toward) and that will be burned up by friction while the bullet is going up and down. In all likelihood it will lose it before it lands. The spin, if not expended, will hold the bullet in the same angle as it was fired, meaning as it falls it will hit rear first and horizontally it will hit from the side.
This is basic physics and vectors. Therefore I maintain my suspicion that the incident was the result of defilade fire, <45 degree angle fire, or shot fired and victim at significantly different heights.

Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 3:23 pm
by WildBill
sugar land dave wrote:This is why I was home under my roof during NYE. In Sugar Land you could hear many gunshots for several hours. What goes up does come down in most cases.
I was astounded by the number of gunshots that I could hear on NYE.
They started around 8PM, I thought that people in my area had better sense.
Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 3:23 pm
by mojo84
I think mythbusters fudged their results some for liability reasons. There is no way a bullet FALLING has the velocity to kill.
Now, a bullet shot at an angle returning to earth on an arc, that's a different story. I also believe the difficulty in finding the shooter is the result of the significant distance the shooter would be from the point of impact.
Think of a hail stone falling from the sky. It takes a significantly large one to kill someone and that is not from penetration but blunt force trauma.
Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 7:06 pm
by jason812
You can take Myth Busterers as a TV show. I wouldn't call it true science but what they did show was a bullet falling also stabilizes side ways. If a bullet were fired almost straight up, it would come down sideways making a puncture wound even more difficult.
Re: Bullet falling from the sky kills Houston man
Posted: Sun Jan 03, 2016 10:35 pm
by The Annoyed Man
Charles L. Cotton wrote:ScottDLS wrote:Vol Texan wrote:I hope they find the idiot who did this:
http://www.houstonchronicle.com/news/ho ... =fb-pemium
Just a few moments into the New Year, Javier Sruarez Rivera stood in his driveway with his wife to watch fireworks burst in the night sky, listening to their pops mingled with the sounds of unseen neighbors shooting guns into the air.
As he looked up, a bullet came down.
Rivera collapsed, falling backward onto the concrete, blood pouring from a wound to his head. Inside his house, 18 family members, who had been sharing midnight hugs and handshakes, heard his wife's screams for someone to call 911.
. . . I believe in most cases terminal velocity for a falling object is about 120 fps or 154 mph. A roughly straight up until it falls back bullet would have lost it's spin and lateral velocity (if any). I guess if it hit you in the eye...or soft tissue of the neck... I highly suspect "defilade" fire. In other words more lateral from a higher vertical location...or maybe even someone with evil intent shooting while covered by celebratory fireworks. . . .

Free-falling rounds simply do not have the energy to penetrate the skull or significantly deep into soft tissue. As The Wall noted, Myth Busters did a segment on this sometime back.
This is terribly sad and so preventable. I hope the person who did this is caught and prosecuted.
Chas.
But Charles, Mythbusters tested literally free-falling rounds that were fired vertically up and came down vertically. Shots fired at an angle into the air can easily carry enough velocity to kill someone far enough away that the shot is never heard - as demonstrated by the two cases I illustrated above. Both patients were hit by rounds fired from far enough away that nobody heard the shot.
Re: Bullet falling from the sky kills Houston man
Posted: Mon Jan 04, 2016 2:16 pm
by stroo
It is extremely difficult to fire straight up. Therefore almost all bullets fired in the air will have a vertical element to them. There are cases every new year where bullets fired in the air have come down and wounded or killed people. There even are regularly reports of bullets going through roofs.
Re: Bullet falling from the sky kills Houston man
Posted: Mon Jan 04, 2016 2:30 pm
by drjoker
Yup, some idiot fired a gun on New Year's in my neighborhood, too. I heard it. I recognize a 9mm round going off anywhere. It was definitely not fireworks. I thought only Bedouin do this. I guess there's idiots in every culture. Ugh.
Re: Bullet falling from the sky kills Houston man
Posted: Mon Jan 04, 2016 5:24 pm
by oohrah
After reading this thread and some of the numbers tossed around, I was curious so I programmed my own simulation, and compared it to Internet research.
I used NASA estimates for drag on a sphere, no spin, and accounted for air density and mass (200 grains) to determine terminal velocity. I calculated values from 200-500 mph, which is not out of line with other estimates. This is assuming a straight vertical drop in a standard atmosphere. Obviously, assumptions have to be made, but they are reasonable. I would not want to get hit with something going that fast, even if it wasn't the pointy end.
As has been mentioned, flying at angle will allow the bullet to retain its spin (and stability) and would be much more lethal. As the mythbusters said: yes, no, and maybe.
Re: Bullet falling from the sky kills Houston man
Posted: Mon Jan 04, 2016 6:19 pm
by Maxwell
mreed911 wrote:Anyone who lives in Houston for any amount of time knows that you GO INSIDE at 10:45 and don't come out until the morning on NYE.
LOTS of cars will have bullet hole damage in them. It's not uncommon for us to find actual bullets (lead+copper) in the parking lots of our stations the morning after.
Excuse me? What part of Houston are you talking about?
Re: Bullet falling from the sky kills Houston man
Posted: Tue Jan 05, 2016 1:28 pm
by mreed911
Maxwell wrote:mreed911 wrote:Anyone who lives in Houston for any amount of time knows that you GO INSIDE at 10:45 and don't come out until the morning on NYE.
LOTS of cars will have bullet hole damage in them. It's not uncommon for us to find actual bullets (lead+copper) in the parking lots of our stations the morning after.
Excuse me? What part of Houston are you talking about?
All of it. For the damage/bullet fragments, I'm specifically speaking about the Aldine area, but no part of Houston is safe from idiots shooting into the air that night.
Re: Bullet falling from the sky kills Houston man
Posted: Tue Jan 05, 2016 4:04 pm
by PaJ
This nearly happened to my dad. As a teen he was hit in the leg by a falling bullet. He heard the sound of the bullet and describes it like a stick being thrown end over end. He thought his brother had thrown a stick at him. Bullet is still in his leg today. Would've done more damage to remove it and it never bothered him, so there it rides. They never found out who shot it.
Re: Bullet falling from the sky kills Houston man
Posted: Wed Jan 06, 2016 9:53 am
by CharlieH
As a skydiver and engineer I want to point out there is no "Terminal Velocity" number in 1 ATM that can be used for simple calculations. A 230 grain 45 ACP round is going to have a MUCH higher terminal velocity than a 115g 9mm, and even more energy.
The equation is

.
If that image doesn't work, here it is in programmer notation.
Terminal Velocity = Sqrt(( 2 * mass * g) / ( p * A * Cd )).
Cd is the hard one. With spin it will be constant, but with a tumbling bullet it will vary. A larger sphere of lead is going to have a much higher mass/area ratio than a small one. No one needs to worry about bird shot raining on them.
But heavier skydivers fall faster and must wear suits with higher drag coefficients to slow down, and light skydivers wear weights.