Originally Posted by Brown Dog
I don't understand your combative "looking for an e-fight" style.
I didn't come here looking for an "e-fight"
In a thread started by AJ
What is long range?
I stated the following...
"The drop of a bullet, no matter what caliber (.22lr to 50BMG) in 3/4 of a second, is just about the same, so the tools and skills to hit with it, would be about the same.
That wasn't a e-fight, it is a true statement.
But bwaites WAS apparently looking for an e-fight, when he said:
"Nope, not "just about", it is the same, unless we have have revoked gravity!! Bill"
So I replied:
"Nope, it's "just about" the same, NOT exactly the same...
... I haven't revoked the laws of gravity, but the laws of aerodynamics's DO come into play.
Some bullet forms (long pointy ones) have a slight lift, compared to the blunter ones like the .22lr, and the 45-70.
So it is "just about" the same..."
Which is a true statement... and any ballistic software will confirm that.
So bwaites shifted the frame of the discussion and started talking about airplane wings and lift... but his "science" was less than shabby.
And it went down hill from there.
Then you jumped in and took something I said, and threw it back out of context.
So that is clear.
This is what I said in the three threads.
A - There are those that believe that bullets turn nose down to follow the tangent of the arc.
This is impossible, because of Newton's laws on motion. It makes no difference what the twist is, or what the spin rate is.
To paraphrase - If a body is in motion, it will NOT change ANY
of the parameters of the motion, unless an external force is applied.
This means, in simple English, if a bullet is launched at upwards at 10°, it cannot change the angle of it's axis, unless a force can either lift the tail end, or pull down the nose..
There is no such force. The aerodynamic force on the bullet at the "center of pressure" is forwards of the center of gravity, so the air flow is trying to push the nose UP, and gravity is trying to pull the tail down.
So there is NO force that would bring the bullet axis tangent to the arc.
That's not my opinion, it is simple physics, and has been confirmed by the military for close to a century - artillery shells fired at long range, do NOT hit point first... they hit still pointing at the angle they were fired. Artillery shells fired at very high angles hit still point at high angles, and the tail end contacts the ground first.
The Annapolis library is filled with pictures of 16" shells falling with the nose still pointing up.
IF bullets followed the tangent of the arc, then there would be NO spin drift - but we KNOW that spin drift exists, even though it is very small at the ranges that riflemen shoot.
The smooth bore mortar drops rounds with the nost pointing down, and ON TRACK (less wind and variables)... but the rifled Four-Duce mortar does NOT - the firing range tables for the four-duce take into account "spin drift"
Spin drift happens because the bullet or artillery shell is NOT falling point first (tangent to the arc), but is falling at a downward angle, with the axis still pointing at the launch angle... this causes the air to flow from somewhat below. Technically, the angle of "attack" of the air flow is equal the the launch angle, plus the fall angle.
This airflow from the bottom of the projectile causes the bullet to crawl right (looking from behind, with CW rifling).
Precession... is the displaced motion of the axis of a rotating body. It is caused by applying force on the axis of a rotation body. The precession is EQUAL to the axis displacement.
If you apply ANY force to the axis of a bullet that is strong enough to move the axis, there will be an equal change in the direction of the axis by 90°.
The nature of this displacement is not to the right as people think (those wanting to believe that precession is the cause of the rightwards drift in bullets)... the actual change in direction of change in a bullet would to the LEFT (looking from the rear).
But we know that "drift", what little there is at short ranges, is to the right.
So what we are left with is this...
There is no explainable force or forces that will meet Newton's requirement to change the direction of the bullet axis.
IF there were such a force, the force trying to make the bullet follow the tangent of the arc, would actually cause the bullet to point left, by the same amount and the total change in the vertical plane... so a bullet at 1,500 yds, would also be pointing some 10° LEFT - and anyone that has shot at that range can tell you that the bullets are not making a large left hand circle. If you don't believe that, go buy a dime store gyroscope and play with it for a day - it will open your eyes to many of the myths in bullet flight.
What I actually said is:
Originally Posted by CatShooter
If you are behind a bullet (or gyroscope) that is rotation clockwise (like a bullet), and you try to raise the back, or lower the front, what happens IMMEDIATELY, is the nose (front) turn LEFT, the exact amount that you raised the rear or lowered the front..[/b]
To which you jumped in, looking for an e-fight:
There's a piece of your reasoning that's barse ackwards:
The airflow is trying to raise the nose -not lower it. The CP is infront of the CG.
As a consequence, all your 'precessional' reasoning is back to front "
I had ALREADY said that. But there is NOT just one force working on the bullet - there are several.
I was talking about precession, and you claimed that my "'precessional' reasoning is back to front".
... which it is not.
I didn't invent precession - it has been known for several hundred years. It ALWAYS works the same, because it is part the the laws of rotational motion, called "the conservation of momentum".
My 'precessional' reasoning" was not back to front. It is what it is.
So it would appear that bwaites was looking for an e-fight, and made a fool out of himself, because he didn't understand what he was talking about. And as his "science" was shot down, he kept changing the frame, and those got shot down too, cuz bwaites just doesn't understand this stuff.
And you jumped into the cat fight, looking for an "e-fight", without reading ALL the threads to this point, or you would have known FULLY what I was saying, and not stooped to misstating what I had said, out of context, just so YOU could join the fray.
None of the above are "my opinions"... they are proven facts. I am just the messenger.
While there are shooters that will continue to believe that a bullet follows the tangent of the arc, they do not, and cannot, for the above reasons.
It is very simple - bullets continue to travel with the axis pointing in the direction they were launched.
At very long ranges, bullets start to crawl to the right (w/CW rotation) due to the air flow under the bullet - just like a curved baseball... this crawl is so slight at rifle ranges, that it gets lost in all the other issues, so it is just about unseen.
... and there is no set of separate laws of physics for large projectiles, that are different than the ones for small projectiles. The laws of rotation bodies, and the laws of physics apply to all objects.
If you or bwaites can change that, then both of you get in the front of the line for a Nobel Prize in Physics, cuz you have radially changes the last 500 years of physics.
"... and a military trained gunnery expert (me).
You joined this cat fight looking for an e-fight... not me. You tossed the first nasty at me - I just responded "in kind".
If you are what you say, then you will fully understand what I have said here... and you know it is true.
If you don't understand what I have said here... well, you know! There are lots of them on the internet.