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
wind drift based on drag
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="LouBoyd" data-source="post: 665774" data-attributes="member: 9253"><p>QUOTE=Mikecr;665677</p><p>>Coefficients aside,,</p><p>>Do lighter bullets cause less drag?</p><p>No drag is a force from the projectile pushing air out of the way. It is independend of bullet weight, However a ligher bullet has less energy to lose so it decellerates quicker.</p><p>> Do they cause less drag due to smaller diameter?</p><p>Yes. The have a smaller volume of air to push out of the way . </p><p>> What if they are the same diameter, but lighter? </p><p>I thought that was your first question. Shape matters too. A streamlined bullet loses less energy pushing air out of the way than the same diameter blunt one. </p><p>> Does higher velocity of this lighter bullet mean higher total drag? </p><p>Drag increases roughly with the square of the velocity, though the complexities of air flow can modify that considerabley, particularly around the speed of sounnd.</p><p></p><p>> Does higher total drag mean greater slowing rate and therefore higher T-Lag?</p><p></p><p>Generally yes. however consider if the higher drag takes the bullet subsonic where the drag may then drop cosiderably. It's possible (though not likely) for the bullet with the higher initialy drag to have less total wind deflection. When it reaches the target. Don't assume that bullets always slow down with distance. High trajectory low drag bullets can decellerate going up and actually accelerate going down if the force of gravity is higher than the drag force over a range of velocities (usually subsonic) velocity. </p><p>Though I believe I understand the math I'm not able to predcit just by looking at the BC's and muzzle velocities which of two bullets will have the greater wind deflection at a given distance. But I do trust the results given by ballistics computers. Few commercial ballistics computers however allow you to enter variable downrange wind vectors. If winds were constant over every path you coudn't miss if you had a Kestrel wind meter at the shooting positiong. Reality is far different. </p><p></p><p>> Not trying to hijack the thread, but to lead into an understanding that might help. </p><p></p><p>The math may be precise, but it's really not of much practical help to the shooter. What is of help is lots of practiece trying to judge downrange winds from the very subtle clues from moving mirage, blowing leaves/grass/trees, and blowing particles in the air. </p><p>That combined with watching bullet point of impact in those condtions can give good results. There are electronic instruments which can predict wind deflection using methods similar to watching mirage. but I don't know of any that are available commercially. </p><p></p><p>Sighter shots work well if you can see the point of impact. The path of the next bullet will be close to the same if conditions aren't changing too fast and the second shot is immediate. It's the best wind meter avaialble to a shooter.</p></blockquote><p></p>
[QUOTE="LouBoyd, post: 665774, member: 9253"] QUOTE=Mikecr;665677 >Coefficients aside,, >Do lighter bullets cause less drag? No drag is a force from the projectile pushing air out of the way. It is independend of bullet weight, However a ligher bullet has less energy to lose so it decellerates quicker. > Do they cause less drag due to smaller diameter? Yes. The have a smaller volume of air to push out of the way . > What if they are the same diameter, but lighter? I thought that was your first question. Shape matters too. A streamlined bullet loses less energy pushing air out of the way than the same diameter blunt one. > Does higher velocity of this lighter bullet mean higher total drag? Drag increases roughly with the square of the velocity, though the complexities of air flow can modify that considerabley, particularly around the speed of sounnd. > Does higher total drag mean greater slowing rate and therefore higher T-Lag? Generally yes. however consider if the higher drag takes the bullet subsonic where the drag may then drop cosiderably. It's possible (though not likely) for the bullet with the higher initialy drag to have less total wind deflection. When it reaches the target. Don't assume that bullets always slow down with distance. High trajectory low drag bullets can decellerate going up and actually accelerate going down if the force of gravity is higher than the drag force over a range of velocities (usually subsonic) velocity. Though I believe I understand the math I'm not able to predcit just by looking at the BC's and muzzle velocities which of two bullets will have the greater wind deflection at a given distance. But I do trust the results given by ballistics computers. Few commercial ballistics computers however allow you to enter variable downrange wind vectors. If winds were constant over every path you coudn't miss if you had a Kestrel wind meter at the shooting positiong. Reality is far different. > Not trying to hijack the thread, but to lead into an understanding that might help. The math may be precise, but it's really not of much practical help to the shooter. What is of help is lots of practiece trying to judge downrange winds from the very subtle clues from moving mirage, blowing leaves/grass/trees, and blowing particles in the air. That combined with watching bullet point of impact in those condtions can give good results. There are electronic instruments which can predict wind deflection using methods similar to watching mirage. but I don't know of any that are available commercially. Sighter shots work well if you can see the point of impact. The path of the next bullet will be close to the same if conditions aren't changing too fast and the second shot is immediate. It's the best wind meter avaialble to a shooter. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
wind drift based on drag
Top