Answer yes or no to form a number on each side.

Question:
Do bullets yaw?

Choices:
YES
NO

 

Yes, but you can reduce yaw by either using a faster barrel twist or a shorter bullet.

Ok, its a near 100% YES for some reason known only to the Gods of the internet...

Soooo why all the negitive posts when I suggested such a phenomenom, the thread had me convienced I was mistaken when I said I thought shooting elephant at 25 yards was a good thing to do because of bullet yaw up close that changed the course of the bullet according to the old time elephant hunters.

Guess those old boys knew a thing or five more than the internet jockies of 2007! but apparantly somewhere in this discussion some learned something and others like self became totally confused. Almost like an arguement with my wife.

Ray,

my wise old grandfather gave me some good advice about women and arguing: "...never argue with your wife. Always try and Negotiate. Never argue, just dicker for a couple minutes and see if the result isn't much better for all involved!".



Rich
DRSS

Ray!
That is only one reason to not get too close. As I have said here before when you get too close your time to react can be shortened dangerously.

But to your question. Yes, all bullets yaw to one degree or another and as 500 grains said sometimes the solution is a faster twist or shortening the bullet. Another is to move the Center of Gravity forward on the bullet.

The amount of yaw (wobble) at the front of the bullet is dependent on the distance from the CG to the point of the bullet. As an example the amount of yaw at a bullets nose whose CG is near the rear of the bullet will be twice as much as the yaw of the same length bullet where the CG is near the mid-point of the bullet. Another example is that if the CG of the bullet is exactly at the mid-point of the bullet a bullet twice as long will have twice as much yaw at the nose. I can't find my high school math book to check the trig functions necessary to compute those numbers.



465H&H

Yes they do yaw, but as Alf commented in an earlier post, close range divergance from a theoretical straight line is best thought of as nutation and precession.
Yaw is as I understand it a long range phenomenon.
It's easy to give yes or no answers but when interrelated variables influence each other, it's not so easy to explain what the yes or no are pointing to, which is why we have theories and models.

I can only hope that my comments are, as my mathmatics professor used to say, no more than approximately wrong.
Alf will, I hope, tell me if I am wrong.

Do bullets Yaw? DUH! Ever measure the concentricty of a group of lets say 50 ,500 gr .458 Hornady RN's? Barnes X bullets? Just how does twist rate correct for a non-concentric bullet? Do you think that magically a precessing bullet just " goes to sleep" with distance? Maybe that fast twist straightens out that non-concentric bullet and makes it spin true about its axis of symetry? NOT! Ever shoot groups with bullets with run-out that varies from .0001 to .010? If so you know, if not you probably also believe in the tooth fairy. Oh Mr. Bill, I forgot a faster twist makes it all better!. Bullshit!-Rob

All projectiles "pitch", "yaw", and "roll". Projectle length has nothing to do with it.

I'm screwed!

Suddenly I don't care anymore!

quote:

I forgot a faster twist makes it all better!. Bullshit!

From the perspective of a bench shooter, you are right. From the perspective of a hunter, you are wrong. The requirements of these two disciplines cannot be reconciled in one bullet/twist combination.

quote:

Projectle length has nothing to do with it.

I ask again:
Buliwyf,
Do you agree with this?

quote:
Caliber - Weight - Twist rate - Bullet length - Stability Factor - Shape
270 ----- 150gr -- 1:10" ------ 31.2mm/1.23" - 1.44 @ 2600fps -- SP BT
270 ----- 150gr -- 1:10" ------ 26.8mm/1.06" - 2.07 @ 2600fps -- RN FB

A stability factor of 1.5 can be had with the Round Nose Flat Base bullet in a twist rate as slow as 1:11.3" while the same weight Spitser Boat Tail needs a twist of 1:9.5" for a stability factor of 1.5.

quote:

Maybe that fast twist straightens out that non-concentric bullet and makes it spin true about its axis of symetry? NOT! Ever shoot groups with bullets with run-out that varies from .0001 to .010? If so you know, if not you probably also believe in the tooth fairy.

Who noticed this? When you balance the wheels of your car at the normal/standard setting they seem to be perfectly balanced. But then ... when you ask them to have it balanced at the "high-speed" setting, then all of a sudden you will find that they were in fact not perfectly balanced and you have to change the weights on the rim!

Now how does this impact on bullets where we opt for faster twists? Problem ... we cannot put weights on the bullets.

Warrior