does a bullet rise?

airbornerizz

September 08, 2012 13:26

This has sparked quite a discussion at work. Here are the 2 schools of thought:

A bullet can not rise past its point of origin.

A bullet will rise about 1/4 to 1/2 inch even from a level point of origin due to barrel rifling.

Who is right??

0

• 

  260

  September 08, 2012 13:32

  gravity is constant. a bullet begins to fall the moment it leaves the barrel. line of sight is straight, therefore we turn the scope to raise the trajectory of the bullet to impact at a given point.
  a bullet will cross line of sight twice. on the rise and on the fall.

  0
• 

  RCrosby

  September 08, 2012 13:51

  +1 260
  This should be a short thread!
  (Interesting, though. I've never heard the argument that the spin imparted by rifling would cause a bullet to rise above the line of bore.)
  Wonder who first came up with that little gem??

  0
• 

  llama

  September 08, 2012 13:57

  quote:Originally posted by RCrosby
  +1 260
  This should be a short thread!
  (Interesting, though. I've never heard the argument that the spin imparted by rifling would cause a bullet to rise above the line of bore.)
  Wonder who first came up with that little gem??
  
  
  Physics wise it is possible... but you'd have to be rotating *very* fast - beyond the speed at which regular bullets can rotate without sudden failure.
  
  Also, given enough forward velocity, you could go "up" as it were, by moving forward fast enough that the earth's curve gives you altitude compared to the constant drop - IIRC from high school this is around 8k fps for escape velocity...

  0
• 

  Ray Boone

  September 08, 2012 14:13

  Comsidering that the drop of a bullet due to gravity will cause the bottom of the bullet to have a higher friction coefficient than the top, and that moving air has less pressure than still air, I'd expect a slight lessening of pressure due to spin and gravity to cause the bullet to dropp faster than gravity alone- but I seriously doubt there is a mechanism that could measure such minute amounts.

  0
• 

  airbornerizz

  September 08, 2012 14:59

  Thanks guys

  0
• 

  Txs

  September 08, 2012 15:41

  quote:Originally posted by airbornerizz
  A bullet will rise about 1/4 to 1/2 inch even from a level point of origin due to barrel rifling.How do those who believe this think rotation causes a bullet to know which way is up?

  0
• 

  gruntled

  September 08, 2012 15:55

  Any rise in the arc is likely due to recoil.
  The amount will be affected by the amount of recoil & the time the bullet is in the barrel (velosity & barrel length).

  0
• 

  tsr1965

  September 08, 2012 16:01

  Gravity has animmediate effect on a bullet, immediately upon it's exit from the crown of the barrel. That is pure physics laws, and they are constant, and true, for at least the last few hundred years.
  
  If a bullet does rise, it is because the barrel is tilted with the muzzle higher than the breech, with the sight(s) aligned at a complimentary angle. It is called trajectory.
  
  It is mythical that the bullet rises, and just as mythical that the bullet doesn't start to get going(pick up velocity), untill after it exits the barrel.
  
  When the bullet exits the barrel, it does two things...begins to drop immediately, and begins to slow down immediately.
  
  Best

  0
• 

  RCrosby

  September 08, 2012 16:12

  Any rise in the arc is likely due to recoil.
  
  Just to set the record straight, I DID KNOW this wouldn't be a short thread. Just that it could have been.
  
  As for the idea that recoil might be a factor, it would only raise the line of bore. As already pointed out, the bullet will immediately start to drop relative to the line of bore at the moment of exit.

  0
• 

  ripley16

  September 08, 2012 16:14

  quote:does a bullet rise?
  
  No it does not. 260 nailed it.

  0

Please sign in to leave a comment.