Wind affects bullets how?
Does wind change the DIRECTION of a bullet, or cause it to DRIFT? Two results if a cross-wind is blowing strongly immediately in front of the muzzle, then after a few yards was calm; if the bullet changed direction, then the results of the wind would increase as the bullet traveled; or if only drifted, the bullet would maintain the same direction, parallel by the amount of change. So which is it?
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The wind really doesn't move the bullet as much as exert a force that causes a redirection to occur. Once the force is exerted on the bullet (like gravity or air resistance) the bullet will continue in an arc in the direction the force is exerted. Simply stated, if the breeze is 90 degrees to the bullet's path (say left to right), the moment the bullet leaves the barrel the wind exerts a force on the left side of it redirecting it to the right. It will continue that arc to the right even if the wind stops, although not as far right. [;)]
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Ray:
What your asking here is a physics question. Part of your question assumes a cross wind at the earliest stage of travel from the barrel. This fact is critical to the discussion because the bullet path is more directly/adversley effected at this stage than at the end of travel or even half way through its trajectory path. You are setting out a hypothetical wherein the bullet path would actually change direction versus a crosswind at the later stages of trajectory where you would be more likely to see bullet drift. The earlier the opposing force (crosswind) is applied the more effect on the bullet path. In application a bullet shot from a windy ridge into a coulee or canyon would have more/greater change in bullet direction, than the same bullet shot from the calm bottom of the coulee or canyon to the top of the ridge. Elevation of course would change; but we're talking about windage variations in addressing your question.0 -
There was a great post on this two-four months ago.
The search feature does not work on my Mac;
Try it on a PC.
I've seen forum-response text highlighted as a result of C&P of a GB search.
So it must be working on some operating systems.0 -
Ray B,Hopefully what these folks have said will help you with your question,But if not I recommend a set of books called Understanding Firearm Ballistics.
Start with vol.I ,some of the stuff in this book may get a little redundant,but you can learn alot from it. (Brush up on your math)[:D] you will need it to understand some of the principals and laws of physics that are referred to in this set.HAVE FUN!
AC Tactical0 -
WIND WILL CAUSE A BULLET TO DRIFT A LITTLE BUT NOT EXACTLY CHANGE THE COURSE OF THE BULLET THE LONGER THE SHOT THE MORE IT WILL DRIFT
ONE SHOT ONE KILL.....
RANGERS LIVE FOREVER0 -
Pretty good article on this subject in last months issue of "Shooting Times". I don't know if it will answer your questions but it does bring up some interesting facts.
BEER IS PROOF THAT GOD LOVES US AND WANTS US TO BE HAPPY!0 -
Ray B,
I'll take one more whack at this just because I hate to give up.
The articles that I listed in response to your question on the other Forum contain the answer to your question but the answer takes some effort on your part for you to be able to discern what the authors are saying since it is a scientific presentation and not meant for us lay people. I am still looking for a simplistic answer that we can all use, maybe with some diagrams. Anyway, here is what I can offer:
Setting the scene; a rifle is level and recoil controlled on a bench. A bullet is fired and right hand spin is imparted to the bullet by the rifling in the barrel. It now has velocity, spin and direction. The bullet exits the muzzle, this being one of the two points where wind can have the most effect on the bullet since the bullet is not yet completely stabilized but trying to achieve stabilization.
This is compared to watching a string activated gyroscope at the beginning of its spinning. It appears to wobble at first, then settles down into the controlled, stable spin that we are used to seeing.
As the bullet leaves the muzzle, a wind from the left strikes it. The bullet moves to the right slightly but remains relatively parallel to its original path. This is referred to as drift when we read exterior ballistic tables. The drift remains parallel to the original line of firing due to the effect of gyroscopic motion; the bullet spinning about its central axis and center of gravity. The whole bullet just moves to the right a bit and stays parallel.
However, there is one more component that gets figured into this system and that is Bernoulli's Rule or Principle. Simply, the wind from the left striking a bullet with a right spin creates two areas of differing pressure; one at the top of the bullet and one at the bottom of the bullet. When viewed from the base of the bullet, the wind blowing across the top is moving in the same direction as the spin, creating an area of lower pressure. The wind blowing across the bottom is counter to the spin, creating an area of higher pressure. This results in a slight lift upwards. The opposite occurs when the wind is from the right. The lower pressure is at the bottom and the greater pressure is at the top creating a downward movement.
I hope that this helps some.
Best.0 -
to further understand the principle nononsense has presented,..do a search on "yaw of repose" or read a book entitled "precision shooting at 1000yds". In addition to upward or downward drift in POI,..there is also an increased or decreased wind drift on the horizontal plane due to the right rotation of the bullet. When presented with a left to right wind,.the bullet with a right rotation has a seperate value of drift other than the wind drift. The right hand drift is increased with a left to right wind,..but decreased with a right to left wind (opposing the bullets rotational direction). For ultra long range hunting (1500+yds) this seperate equation must be calculated and integrated into your balistics table to figure your "true" windage adjustment. To make it all the more interesting,..it also changes with the altitude and the subsequent change in air density and humidity. [;)]
why chase the game when the bullet can get em from here?....
Got Balistics?0 -
Originally posted by nononsense
Ray B,
Setting the scene; a rifle is level and recoil controlled on a bench.
I agree with everything you said but I don't think you want your rifle level. Gravity might work its effect before some of the wind effect might be evidenced.0 -
Checkout the June 2004 issue of www.SHOOTINGTIMES.COM
Great article, page 64....
BE SAFE!! Buffler0 -
a solid object like a rock will change the direction of a bullet if it hits it. the wind causes it to drift. a bullet travelling away from you is going 'away.' away is a direction. if it drifts a little right or left...its still going 'away' or forward. forward is a direction. if it hits a rock and richochetes left...'left' is a different direction. the wind doesnt change the direction of a bullet. solid objects do. kiss folks...(k)eep (i)t (s)weet and (s)imple.[;)]
former air operations officer SEAL Delivery Vehicle Team 2. former navy skeet team, former navy rifle/pistol team member. co-owner skeetmaster tubes inc.. owner/operator professional shooting instruction.0
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