Oh Boy! Physics! - Page 4
You are Unregistered, please register to use all of the features of FirearmsTalk.com!    
Firearm & Gun Forum - FireArmsTalk.com > Long Guns > .22 Rifle/Rimfire Discussion > Oh Boy! Physics!

Reply
 
LinkBack Thread Tools Display Modes
Old 10-29-2012, 06:32 AM   #31
Feedback Score: 0 reviews
 
Join Date: Feb 2011
Location: West, by God, Funroe,Louisiana
Posts: 18,707
Liked 9209 Times on 5058 Posts
Likes Given: 74

Default

Thread went from this...

Quote:
Originally Posted by Vincine
This is from another forum and concerns .22lr long range shooting. What do you guys here know about this? So the rotational speed of a bullet interacting with a side wind has a larger effect on its trajectory than the amount of time a bullet is subjected to the side wind??

Higher speed bullets have a flatter trajectory than lower speed bullets. Under 'No Wind' conditions, the higher speed bullet will be more 'accurate'. That is, it requires less adjustment of POA than a slower speed bullet.

This implies that there is a wind speed/bullet fps crossover point at which the flatter trajectory of the higher speed bullet is negated by the effect of a side wind. Right?
To this.

Quote:
Originally Posted by Eturnsdale

Hold on a sec. <looks in her pants> Yup an inny.

I enjoyed our chat as well.
Just one of the reasons I love this forum!
__________________
trip286 is offline  
2
People Like This 
Reply With Quote
Old 10-29-2012, 11:14 AM   #32
Feedback Score: 0 reviews
 
Join Date: Apr 2012
Location: Va. mnts
Posts: 210
Liked 32 Times on 27 Posts
Likes Given: 16

Default

The one son thats still living at home(moving out after huntin season,which is rediculously funny........he's going to miss home cooking AND Deer whackin)


He graduated first team accademics with a dble major....Math and Physics.His answer was "beats me".Well,it was a little more involved....something about models and parameters in physics being pulled out of ones arse,or some such.IOWs,you can change a cpl things and sort of swing results in different ways....all brain numbing.

I'm only slightly more interested.I like to know a few terms and relationships....but like #3 son above,can pretty much throw wrenches in the discussion at will.And not for reasons of argument...more to show how little things can skew results.One for instance is most folks take for granted a projectile has "perfect" balance........uhhh,they don't.Its like a "straight" arrow.Straight to what degree?Just sayin....I'm more of a test it and see if you can get things clear in "your" mind.

I will say....from shooting tournament archery that a "bent" arrow.....(and "how bent" affects this)....will and does "go to sleep" at some point in its rate of rotation and velocity.The more bent,the longer(translates to slower)it takes on the flight path,to go to sleep.

__________________
Intheshop is offline  
 
Reply With Quote
Old 10-29-2012, 11:54 AM   #33
Feedback Score: 0 reviews
 
Vincine's Avatar
 
Join Date: Jun 2011
Location: Adirondack Mts.
Posts: 3,495
Liked 1910 Times on 989 Posts
Likes Given: 1455

Default

Quote:
Originally Posted by Intheshop View Post
. . . . .I will say....from shooting tournament archery that a "bent" arrow.....(and "how bent" affects this)....will and does "go to sleep" at some point in its rate of rotation and velocity.The more bent,the longer(translates to slower)it takes on the flight path,to go to sleep.
Please do continue. Tell us all about how the degree of flex in the shaft, affects the 'archer's paradox'. I promise I won't go to sleep.
__________________
"Sometimes I pretend to be normal, but it's boring and I go back to being me."
"You might as well be yourself, people won’t like you anyway."
"Tres verbo dictom"
Vincine is offline  
 
Reply With Quote
Old 10-29-2012, 01:41 PM   #34
Feedback Score: 0 reviews
 
Eturnsdale's Avatar
 
Join Date: Sep 2012
Posts: 1,211
Liked 643 Times on 398 Posts
Likes Given: 219

Default

Quote:
Originally Posted by Vincine View Post
I don't know that that's what we all were saying, but what you're saying sounds right.
I was saying exactly what TCH2FLY said, but in what I thought were much more simple terms.

Quote:
Originally Posted by TCH2FLY View Post
The RPM (revolutions per minute) of the round will increase with velocity using a given twist.

muzzle velocity fps x (12/twist rate in inches) x 60 = rpm of bullet
1020fps x (12/16) x 60 = 45900 rpm
1270fps x (12/16) x 60 = 57150 rpm
Quote:
Originally Posted by trip286 View Post
Thread went from this...



To this.



Just one of the reasons I love this forum!
It happens so naturally sometimes.
__________________

“Every person's life is theirs by right. An individual's life can and must belong only to to himself, not to any society or community, or he is then but a slave.”

“If you are unwilling to defend your right to your own lives, then you are merely like mice trying to argue with owls. You think their ways are wrong. They think you are dinner.”

“Pity for the guilty is treason to the innocent."

“Not everyone is willing to embrace liberty; liberty requires not just effort, but risk. Some people choose to delude themselves and see their chains as protective armor.”

Eturnsdale is offline  
 
Reply With Quote
Old 10-29-2012, 01:55 PM   #35
Feedback Score: 0 reviews
 
Vincine's Avatar
 
Join Date: Jun 2011
Location: Adirondack Mts.
Posts: 3,495
Liked 1910 Times on 989 Posts
Likes Given: 1455

Default

Quote:
Originally Posted by Eturnsdale View Post
I was saying exactly what TCH2FLY said, but in what I thought were much more simple terms. . . .
Initially I was asking about the effect on a bullet when the wind flows over the top of the bullet in the same direction of the its spin vs. when it flows over the top of a bullet in the opposite direction of its spin. I forget which causes lift and which causes drop. Apparently it’s NOT called the Magus Effect. This is a separate issue from wind drift and transonic issues which would occur in either case. But then thread explored other ballistic (& non-ballistic ) issues as well, which is okay with me.
__________________
"Sometimes I pretend to be normal, but it's boring and I go back to being me."
"You might as well be yourself, people won’t like you anyway."
"Tres verbo dictom"
Vincine is offline  
 
Reply With Quote
Old 10-29-2012, 02:40 PM   #36
Feedback Score: 0 reviews
 
Join Date: Oct 2008
Location: Idaho --,Happy
Posts: 1,905
Liked 341 Times on 237 Posts
Likes Given: 38

Default

Quote:
Originally Posted by pranc2 View Post
the speed of sound is a majority of the time well above 1080fps it is only that low with high altitude and or cold weather because the air is thinner. at sea level and 70 degrees F the speed of sound is around 1165 fps. the trans-sonic flight is affect more in a .22 because of more drag or ballistic coefficient ( someone did say that) and the mass. A .308 weighs at least 4 times as much and streamed lined. Even in trans-sonic flight the .308 is more predicable.
I live at 6300' above sea level
__________________
Flat Tire is offline  
 
Reply With Quote
Old 10-29-2012, 02:52 PM   #37
Feedback Score: 0 reviews
 
Vincine's Avatar
 
Join Date: Jun 2011
Location: Adirondack Mts.
Posts: 3,495
Liked 1910 Times on 989 Posts
Likes Given: 1455

Default

SoS @ 6300' = 1034.5 fps @ 45F

http://www.engineeringtoolbox.com/elevation-speed-sound-air-d_1534.html

__________________
"Sometimes I pretend to be normal, but it's boring and I go back to being me."
"You might as well be yourself, people won’t like you anyway."
"Tres verbo dictom"
Vincine is offline  
 
Reply With Quote
Old 10-29-2012, 02:53 PM   #38
Feedback Score: 0 reviews
 
Eturnsdale's Avatar
 
Join Date: Sep 2012
Posts: 1,211
Liked 643 Times on 398 Posts
Likes Given: 219

Default

Quote:
Originally Posted by Vincine View Post
Initially I was asking about the effect on a bullet when the wind flows over the top of the bullet in the same direction of the its spin vs. when it flows over the top of a bullet in the opposite direction of its spin. I forget which causes lift and which causes drop. Apparently it’s NOT called the Magus Effect. This is a separate issue from wind drift and transonic issues which would occur in either case. But then thread explored other ballistic (& non-ballistic ) issues as well, which is okay with me.
Yeah, if you ask five people you will get six different answers. Though from most of the physics folks Ive talked to say there isn't any lift from air transfer over or under a spinning projectile unless it is completely spherical.

But then again to see that a bullets shape will alter it's drop all you have to do is look at two different bullets, of the same weight fired at the same velocity to see this.

Maybe I am getting off track again.
__________________

“Every person's life is theirs by right. An individual's life can and must belong only to to himself, not to any society or community, or he is then but a slave.”

“If you are unwilling to defend your right to your own lives, then you are merely like mice trying to argue with owls. You think their ways are wrong. They think you are dinner.”

“Pity for the guilty is treason to the innocent."

“Not everyone is willing to embrace liberty; liberty requires not just effort, but risk. Some people choose to delude themselves and see their chains as protective armor.”

Eturnsdale is offline  
JTJ Likes This 
Reply With Quote
Old 10-30-2012, 03:31 AM   #39
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
Join Date: Aug 2011
Location: Detroit,mi
Posts: 3,268
Liked 1189 Times on 706 Posts
Likes Given: 241

Default

Quote:
Originally Posted by Intheshop View Post
I will say....from shooting tournament archery that a "bent" arrow.....(and "how bent" affects this)....will and does "go to sleep" at some point in its rate of rotation and velocity.The more bent,the longer(translates to slower)it takes on the flight path,to go to sleep.
Anybody else think of LaMont from revenge of the nerds?
__________________
partdeux is offline  
vincent Likes This 
Reply With Quote
Old 10-30-2012, 03:51 AM   #40
Feedback Score: 0 reviews
 
vincent's Avatar
 
Join Date: Oct 2010
Location: MLF
Posts: 4,122
Liked 1960 Times on 1032 Posts
Likes Given: 4288

Default

Quote:
Originally Posted by partdeux View Post
Anybody else think of LaMont from revenge of the nerds?
Now I did...and his limp wristed throwing style!!!
__________________
EFFIN' TOF...
vincent is offline  
 
Reply With Quote
Reply

Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Firearms Forum Replies Last Post
Snipers Math and Physics luisdurazo95 Optics & Mounts 19 08-06-2012 11:47 PM
Question about media/gun physics runewood The Club House 8 04-09-2009 02:51 PM