Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Bullet lift, does it exist?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="AJ Peacock" data-source="post: 177487" data-attributes="member: 4885"><p>CatShooter,</p><p></p><p>Just wanted to let you know, that you got me thinking enough about this stuff, to actually dig out my copy of "Hatchers Notebook". There is a short section on page 555 that anyone reading this thread might be interested in. Of course, since most of the folks reading this probably don't have a copy. And may not even know who Julian Hatcher is, I'll include it here (I'm sure he won't mind ;-0 ). The comments in ()'s and CAPS are mine.</p><p></p><p>------------------------</p><p></p><p>Action of the Air</p><p></p><p>The air not only tries to hold the bullet back, but also causes it to drift in the direction of the spin. The action is as follows: as the bullet starts to fall from the action of gravity after it has started its flight, the air pressure under its point causes the point to deviate in the direction of rotation, because of the fact that the rapidly rotating bullet acts as a gyroscope, and any pressure causes the axis of rotation to swing at right angles to the direction of the pressure. Thus if the bullet is rotating to the right, the upward pressure on the nose causes it to swing very slightly toward the right, and as the bullet presents its elongated surface to the air resistance (BECAUSE THE POINT DOES NOT FOLLOW THE ARC OF TRAJECTORY!!), it is shoved bodily over to the right. The amount of drift is not great; in the service .30 M2 bullet it amounts to 6.7 inches to the right at 1000 yards.</p><p>While the most important effect of air resistance in exterior ballistic calculations has to do with the retardation of the bullet, the action of the air also makes necessary the provision of rifling, so that subject will be discussed here to get it out of the way before studying the effects of retardation of the bullet by the air.</p><p></p><p>-----------------------</p><p></p><p>Since Julian Hatcher believed that the air pressure increased under the nose of the bullet, I would wager that bullets tend to 'sail' or colloquially 'have lift'.</p><p></p><p>Later, </p><p>AJ</p></blockquote><p></p>
[QUOTE="AJ Peacock, post: 177487, member: 4885"] CatShooter, Just wanted to let you know, that you got me thinking enough about this stuff, to actually dig out my copy of "Hatchers Notebook". There is a short section on page 555 that anyone reading this thread might be interested in. Of course, since most of the folks reading this probably don't have a copy. And may not even know who Julian Hatcher is, I'll include it here (I'm sure he won't mind ;-0 ). The comments in ()'s and CAPS are mine. ------------------------ Action of the Air The air not only tries to hold the bullet back, but also causes it to drift in the direction of the spin. The action is as follows: as the bullet starts to fall from the action of gravity after it has started its flight, the air pressure under its point causes the point to deviate in the direction of rotation, because of the fact that the rapidly rotating bullet acts as a gyroscope, and any pressure causes the axis of rotation to swing at right angles to the direction of the pressure. Thus if the bullet is rotating to the right, the upward pressure on the nose causes it to swing very slightly toward the right, and as the bullet presents its elongated surface to the air resistance (BECAUSE THE POINT DOES NOT FOLLOW THE ARC OF TRAJECTORY!!), it is shoved bodily over to the right. The amount of drift is not great; in the service .30 M2 bullet it amounts to 6.7 inches to the right at 1000 yards. While the most important effect of air resistance in exterior ballistic calculations has to do with the retardation of the bullet, the action of the air also makes necessary the provision of rifling, so that subject will be discussed here to get it out of the way before studying the effects of retardation of the bullet by the air. ----------------------- Since Julian Hatcher believed that the air pressure increased under the nose of the bullet, I would wager that bullets tend to 'sail' or colloquially 'have lift'. Later, AJ [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Bullet lift, does it exist?
Top