Bernoulli Principle with Bullets

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Discussion Overview

The discussion revolves around the application of Bernoulli's principle to the behavior of long-range sniper bullets, particularly in relation to the effects of gyroscopic spin and aerodynamic forces. Participants explore the implications of bullet spin on trajectory stability and aerodynamic drag, as well as historical innovations in artillery design.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether Bernoulli's principle can be applied to bullets, suggesting that pressure differences due to rotation may play a role.
  • Another participant asserts that the spin of a bullet primarily generates angular momentum to maintain a straight trajectory, likening it to the stabilization of a bicycle.
  • A different viewpoint emphasizes that the spin does not create lift since the circumferential velocity induced by the spin is uniform around the bullet.
  • One participant expands on the discussion by noting that crosswinds can affect bullet trajectory, introducing forces that depend on both the bullet's spin and the wind direction.
  • A historical reference is made to Gerald Bull's work on artillery shells, which involved innovations to reduce aerodynamic drag and increase range, suggesting potential applications to sniper bullet design.

Areas of Agreement / Disagreement

Participants express differing views on the role of Bernoulli's principle and the effects of bullet spin, indicating that multiple competing perspectives remain without consensus.

Contextual Notes

Some assumptions about the effects of spin and aerodynamic forces are not fully explored, and the discussion does not resolve the applicability of Bernoulli's principle to bullets.

sooty1892
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Hi
I was reading about long range sniper bullets been affected by gyroscopic affect with the spin of the bullet. I was wondering if Bernoulli's principle could be applied to this, as the pressure at one side of the bullet is greater than the other (depending on the rotation).
Is this true and if so, how can it be applied?
Thanks
 
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I always thought bullets used spin to generate angular momentum so that they stay going straight out of the muzzle (like how a bicycle is stabilized by the rotation of its wheels).
 
The spin of a bullet keeps it moving (nominally) straight. It does not provide any lift due to the fact that there is no circumferential velocity around the bullet except that induced by the spin, and the spin-induced velocity is the same everywhere.
 
To expand on what bonehead said, in practicality, there is almost always some crosswind component between the sniper and the target. And this WILL cause the bullet to produce a force, which is dependent on the bullets spin as well as the direction of the crosswind.
 
Modern long-range shells are bullet shaped too. The late Gerald Bull was an artillery designer reputedly assassinated by the Mossad for helping Saddam Husein make a supergun capable of reaching Israel from Iraq.

Prior to that work he developed an artillary shell which had a controlled burn of a propellant in the back. The purpose was not to propel the shell but to fill in the vacuum behind the shell as it flew. This one innovation cut the aerodynamic drag on the shell in half and doubled the range of the conventional artillery shell.

A long-range sniper bullet could be designed using this same principle.
 

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